9 ms·

Jailbreaking the Kindle

306 points by bdelay 10y ago

jonahx 10y ago
Could anyone knowledgeable about this explain what you can do with a jailbroken kindle that you cannot do with a locked one?
- joezydeco 10y ago
  You mean besides what was mentioned in the article?
  - jonahx 10y ago
    Afaict, it's entirely a technical writeup about how to jailbreak. From the intro: "This document details the steps and thought processes I went through when developing the jailbreak. Ideally this will be a useful map or starting point for anyone looking at the system in the future". I didn't find any information aimed at users of the Kindle about why they'd want to jailbreak.
    - jasode 10y ago
      I assume gp was talking about the 7th paragraph mentioning "whys" such as epub, fonts, screensavers: >The mobileread community has done a great job developing extended functionality of the readers. Some of the more popular packages involve an open-source alternative reader with ePub support, a plugin to change fonts, and another addon to enable custom screensaver images.
- replax 10y ago
  Well, the kindle runs essentially Linux so by jailbreaking it you gain the ability to launch arbitrary code! Eg alternate pdf readers, games, ssh, vim and a lot more which can be very useful (especially the off reader KOreader)! check out mobilereads forums if you want to know more about that, it's a vibrant community.
  - dharma1 10y ago
    Is it usable in a beach situation, if you really need to hack away in bright sunshine?
    - emodendroket 10y ago
      This is precisely the scenario e-ink excels in.
    - lj3 10y ago
      This guy thinks so: https://tinyapps.org/docs/e-ink-monitor.html https://tinyapps.org/docs/e-ink-monitor.html
      - dharma1 10y ago
        Nice. I wonder if you could do away with the laptop altogether, and just use your phone with the Kindle, maybe with a bluetooth keyboard for the kindle (for some light work on a beach). Or if there are any other e-ink tablets that run a full linux (cli) or Android?
        lj3 10y ago
        There are eink readers that are easier to hack, like the Kobo, but they're all limited in that they're e-readers and have the minimal processing power to match. The only full on eink tablet I know of is this one[0] which technically doesn't exist yet. It's fully funded, though, so I'm excited to see if it actually ships. [0]: https://www.indiegogo.com/projects/13-3-inch-android-e-reader#/ https://www.indiegogo.com/projects/13-3-inch-android-e-reade...
        dharma1 10y ago
        That 13.3 e-ink tablet looks pretty tasty, I hope it materialises. I suppose you could run VNC on your Android/Ubuntu phone, and just use the e-ink tablet as a thin client. Maybe the slow redraw of e-ink would suck for real work, unless there are ways to make it more palatable for terminal work
- deleted 10y ago
  [deleted]
- rmi_ 10y ago
  Probabaly remove the ads from the subsidised version.
  - ArtDev 10y ago
    This part is easy. Just remove/replace the ad images and keep it on airplane mode. I still plan to jailbrake when I get around to it
- gadders 10y ago
  Not related to this hack, but I did see a post from a guy once that hacked his girlfriend's kindle so the screen saver showed the cover of "Mein Kampf" as a prank.
- zyxley 10y ago
  What I'd really like to see, personally, is Dropbox syncing over wifi with an arbitrary library of ebooks.
  - semi-extrinsic 10y ago
    On stock (and jailbroken) Kindles you can send PDFs or MOBIs to username@kindle.com and have them auto-downloaded to your Kindle. Many people use Calibre[1] (FOSS, win/mac/linux) to sync/manage their ebook collection using this feature. You could easily couple it with Dropbox. You can also use Calibre to have newspapers/magazines sent to your Kindle every morning. There's tons of recipes for scraping BBC, NYTimes, WaPo or $local_paper, rendering with custom CSS to get readable ad-free version, converting to MOBI and sending to Kindle. There has even been SaaS offerings running hosted Calibre cronjobs with user-provided recipes. Not sure if any still exist. [1] https://calibre-ebook.com https://calibre-ebook.com
    - zyxley 10y ago
      > On stock (and jailbroken) Kindles you can send PDFs or MOBIs to username@kindle.com and have them auto-downloaded to your Kindle. That's no good for me because I tend to do a lot of random edits of my epub collection to fix editing errors, replace cover images with better ones, etc. The reason I want Dropbox is to automatically propagate changes like that, not just to transfer files over.
      - semi-extrinsic 10y ago
        Upstream comment recommends running KOreader on jailbroken Kindle for (amongst other things) syncing with Calibre. I'm assuming this is two-way sync, but I don't know.
- semi-extrinsic 10y ago
  I've jailbroken mine to have custom covers. Instead of famous dead American authors I've never read, I have famous dead physicists whom I've actually read and whom I admire.
  - chadgeidel 10y ago
    I'd love to do this using "pulp" science fiction book covers. I assumed that there was already a tutorial for this, but my Google-fu is weak. Did you use a guide or just DIY? What size/resolution image does the Kindle expect? Is there a filename format or a directory structure to use?
    - semi-extrinsic 10y ago
      Here you go (there is a link on that page for latest Kindle's, this is for v. 1/2/3/4: http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for_all_2.x,_3.x_%26_4.x_Kindles http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for... Image format is grayscale 800x600 (bigger for Kindle DX) png or jpg. For best quality I recommend fiddling a bit with the color to grayscale work in Gimp or Photoshop, especially if the image has large areas with soft gradients. IIRC, running a selective Gaussian blur after grayscaling, and/or working the curves tool a bit before grayscaling, will improve problematic images quite a bit. Early models had only 4 grayscales, now they have 16. "Posterize" to 4 or 16 colors after grayscale in Gimp will give you a good idea of how the end result looks.
    - DanBC 10y ago
      I think you want screensaver hacks. Here's one example, but there are others. http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for_all_2.x,_3.x_%26_4.x_Kindles http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for... Some people add their contact details to the screensaver images, so if you lose your kindle your contact details are the first thing someone who finds it will see.
      - rsync 10y ago
        Maybe a better hack would be to disable screensavers since they serve no purpose on an e-paper display and actually cost battery to switch from text -> screensaver -> text. The better behavior would be to not flip the screen at all and keep it static, using no battery.
- bdelay 10y ago
  As mentioned, I think the most popular use is for custom covers. Recent firmware versions show that Amazon might be slowly working towards this as a feature. As the guy who wrote this, I don't use any of the addons. Just did it for fun.
- ptero 10y ago
  I like to be able to read books in other formats (FB2 is a prime example) and use custom readers (e.g., I like coolreader for its configurability). I think neither is an option with Kindle, so I use a rooted Nook. However, I like Kindle hardware a bit more, so I would probably switch if it can be unstuck from using the Amazon default software choices.
- rwmj 10y ago
  I turned mine into a little status display, showing today's weather (and a few other geeky things, but that's the main one). The combination of very low power usage and readable e-Ink display is great. Also older models are very cheap -- mine was £50 including delivery. You can find tutorials for doing this all over the place, eg https://www.youtube.com/watch?v=Oel08SDFyIY https://www.youtube.com/watch?v=Oel08SDFyIY (not the particular one I used, but he's done a very similar job to mine).
- Applejinx 10y ago
  I can tell you what I'd like to do with my Kindle, that's absolutely worth jailbreaking it. I use it for my own .mobi files from a variety of sources, including books I wrote myself. I purchased mine and paid to have no advertising on it. I would roll back to the previous operating system, which did not have advertisements on the homescreen and did not make me navigate two levels deep just to get past subfolders and a 'downloaded' option hiding my own books from me by default, and I would remove its ability to update itself or do anything via wi-fi. I would just connect it via USB for all file management, and that would be perfect for me. Needless to say, I'm really frustrated with the 'update' I never asked for OR installed, which has screwed up these things. I am very, very interested in what can be done with this jailbreaking. All the more as I don't wish ever to purchase a book through Amazon again, if this is the direction they're going. And they are, they obviously are.
  - int_19h 10y ago
    One nifty trick that I found few people know about, is that you can upload your own .mobi books into the Kindle cloud. Just use the email that they provide to upload PDFs and the like. Once the books are there, they show in your cloud collection and are available for download, same as Amazon-purchased books. Better yet, you will also get cloud sync across devices for current location, bookmarks etc - probably the most enticing reason to go down this route. (Not sure if this is helpful to you, if you really prefer to manage files directly via USB. But might be helpful to someone else.)
  - S4M 10y ago
    The first thing I did was to turn off the wifi on my kindle, so I don't have to deal with upgrades or ads. And somehow I can add my own .mobi file to my kindle via usb. I added pdfs I converted to .mobi that way (with some software I found through a google search).
  - dublinben 10y ago
    It sounds like you should just buy a different e-reader then. The kindle is not the right product for you.
- cpayne 10y ago
  I was thinking the same thing... I can only think of "bragging rights" or a learning experience. Although I think this is what makes the (internet) world awesome at the moment. The author sounds like they were mucking around to see how far they could get. Put some thoughts down for others to read and who knows? Whenever we're recruiting, we always look for interesting things a candidate has done. Something like this will easily get you a first interview...
Zombieball 10y ago
Not sure if you are the author or just sharing. If you authored this I would highly recommend mentioning which "kindle" this is applicable to as the first topic. There are multiple generations of kindle e-readers and kindle tablets. It's not readily apparent up front as to which this is applicable to.
- SippinLean 10y ago
  >every Kindle with a 5.6.5 firmware release
  - softawre 10y ago
    You may want to mention what firmware version.
- dflock 10y ago
  > At the time, the jailbreak opened up every Kindle with a 5.6.5 firmware release.
  - deleted 10y ago
    [deleted]
- takeda 10y ago
  The first paragraph says "This is a write-up on the development of the Kindle 5.6.5 Webkit based jailbreak released in February 2016. At the time, the jailbreak opened up every Kindle with a 5.6.5 firmware release."
  - Zombieball 10y ago
    I read this. Which meant nothing to me. Kindle e-reader? Do all e-readers have the same OS? Granted I may not be the target audience. Presumably some one looking to jailbreak their e-reader may have recognized this right off the bat. As someone who recently purchased a cheap kindle fire tablet, and was interested in the possibility of jail breaking, I was confused. Edit: great post though! I researched previously in jail breaking kindle e-readers with not so much luck. Ever since I saw AWS use them as displays for snowball devices I started to see potential for other uses. Will have to try this out.
david-given 10y ago
I did some playing with a Kindle 3 a few years back --- I was writing programs that integrated into the native UI. I built an app which was a Javascript interpreter bolted onto a VT52 terminal emulator. You could type in programs and run them! Using the K3's fiddly little keyboard! Um, awesome. http://cowlark.com/kindle/javascript.html http://cowlark.com/kindle/javascript.html This was on the 3.1 firmware, so it's likely all completely obsolete on modern devices. ...the 3.1 firmware was terrible. It was all Java based, but Java 1.4. No generics! No autoboxing! No foreach! People forget just how awful early versions of Java were in comparison to what we have today. I ended up building a toolchain using RetroWeaver to convert modern Java bytecode into something that would run on the Kindle. Also, the firmware was based on the Personal Basis Profile 1.1. Think back, way into the past, before there were smartphones and Android and iOS... back to the heyday of the downloadable Java applet for your T9-based phone. Yup, that. Kindle apps were midlets, and anyone who remembers writing programs for midlets will be shuddering by now. And it gets worse! The Kindle ran the entire UI, third-party applications included, in a single Java VM. It was as fragile as hell, and it tended to silt up with un-garbagecollectable data until it crashed and rebooted. If you left a thread running on application exit, it would crash and reboot. If your app hung you had to power cycle the device. I believe that the reason why Amazon never really opened up the Kindle to large-scale third party apps was mainly embarrassment. Good times. Good times...
- esrauch 10y ago
  I was an intern on a team that did some Kindle work in 2010 and the Java limitations at that time were definitely a very real annoyance for internal code: they didn't do anything like you are describing for Java bytecode conversion for 1p development to make it less annoying. The issue was maybe even deeper than you noticed, core parts of the API like String.substring() weren't implemented and would just throw a runtime exception.
  - david-given 10y ago
    You mean... you wrote Java 1.4 by hand? I'm so, so sorry.
- 10y ago
mintplant 10y ago
I wouldn't use my Kindle half as much if it weren't for KOReader [0]. Ironically enough for a dedicated reading device, Amazon's built-in reader app pales in comparison to this third-party tool. The killer feature for me is on-the-fly column splitting and text reflow, with the ability to flip to the original page view by tapping a corner -- this is critical for reading academic papers, which tend to be two-column PDFs. It also features contrast adjustment, more fonts, stylesheets, wireless syncing with Calibre, and support for many more file formats including ePub. There's also a Gargoyle [1] port for interactive fiction on the go. It's less practical due to the input lag on the Kindle keyboard, but I still pull it out every now and again. [0] https://github.com/koreader/koreader https://github.com/koreader/koreader [1] http://www.fabiszewski.net/kindle-gargoyle/ http://www.fabiszewski.net/kindle-gargoyle/
- josteink 10y ago
  > - this is critical for reading academic papers, which tend to be two-column PDFs Kindle's and PDFs goes together badly. This is common knowledge. My solution is only using web-pages based formats like mobi or epub based books. The rest... Let's say they don't get in my reading list. Just like the web is nicer without flash, ebooks are just nicer without publishing formats like PDFs which natively can't support reflow or anything super basic required for easy reading.
  - deleted 10y ago
    [deleted]
  - throwawayIndian 10y ago
    > Just like the web is nicer without flash, ebooks are just nicer without publishing formats like PDFs. Web is nice because of flash. The video tag in HTML5 happened only after successes of services like Youtube and Vimeo and hundreds of others after they set off on their paths with Macromedia flash. Stop fooling yourself with that kool-aid against flash in recent years. It's dated for sure, but credit be given where credit is due.
    - 10y ago
criddell 10y ago
All I want is an e-ink device that I can use with books purchased from Amazon, Apple, Google, B&N, and other vendors. Why is that so hard?
- cheeze 10y ago
  $$$
- ArtDev 10y ago
  Check out the Kobo.
  - criddell 10y ago
    I have. Last time I checked, the Kobo couldn't open DRM protected books from Amazon.
    - dublinben 10y ago
      It can if you remove the DRM from them. Amazon is selling you a broken product, so I don't recommend buying books from them anyway.
      - criddell 10y ago
        True, but I wouldn't care about DRM if I could still buy books at any bookstore. DVD's and Blueray disks have DRM, but I can buy one from any store and it will work with my player and my TV. It doesn't seem like a lot to ask for.
enthdegree 10y ago
How do you get the background to pursue this sort of thing? I've programmed and used Linux for a little while and I've done some simple things in assembly language (although not in much depth), but all the technical things past the CVE-2013-2842 section are impenetrable to me.
- bdelay 10y ago
  Started out cracking software on embedded systems a long time ago. That led to an understanding of ASM and reverse engineering. Going from there to exploitation isn't a giant leap. There's quite a few books on the subject. Hacking: The Art of Exploitation is a decent hello world introduction to the subject. Reading CTF practice problem writeups and then trying easier ones yourself are also good experiences. For REing, http://crackmes.de http://crackmes.de is a blast. The entry level challenges should be easy to grasp after reading a few tutorials. Would recommend running everything in a Windows VM. ;) Good luck!
Steeeve 10y ago
The more I see writeups like this, the more I wonder if the effort being laid out by the people doing the work is compensated appropriately. I'm not sure what Amazon pays for identifying a security flaw, but I imagine it's somewhere between $5 and $15k. Having success monthly might yield reasonable compensation, but companies only pay when a flaw is identified, which means you don't get paid for your work, you get paid for your successful work. And you don't get to define what is successful, nor is there usually a clear definition of what successful actually means. I understand that many people do this to get a job in security / security research, but it just seems like the effort-to-payoff ratio still favors people using their found exploits for evil dramatically. There really should be a different pricing model around security exploits - one that encourages responsible disclosure more heavily.
- bdelay 10y ago
  I don't believe Amazon officially pays for security flaws. They ended up sending me a free Kindle (pretty funny) and got an interview out of it. That didn't end up going anywhere, but I got a heck of a lot further than the black hole that is most job application processes these days. Seemed like a fair trade considering the market for Kindle 0days is somewhere near $0. It's a neat project to talk about during interviews. Nothing more.
Steeeve 10y ago
The more I see writeups like this, the more I wonder if the effort being laid out by the people doing the work is compensated appropriately. I'm not sure what Amazon pays for identifying a security flaw, but I imagine it's somewhere between $5 and $15k. Having success monthly might yield reasonable compensation, but companies only pay when a flaw is identified, which means you don't get paid for your work, you get paid for your successful work. And you don't get to define what is successful, nor is there usually a clear definition of what successful actually means. I understand that many people do this to get a job in security / security research, but it just seems like the effort-to-payoff ratio still favors people using their found exploits for evil dramatically. There really should be a different pricing model around security exploits - one that encourages responsible disclosure more heavily.
pavanlimo 10y ago
I was recently researching ebook readers and found Kobo devices way better than Kindle (and cheaper too). Especially for somebody who is a power user of devices. Without getting into specifities, I found that in general Kobo is more open.
wineisfine 10y ago
Btw here is a webservice that converts and sends ePub's to your kindle, without having to use Calibre yourself http://www.sendepubtokindle.com http://www.sendepubtokindle.com
geniium 10y ago
Maybe that'll make Amazon update their Kindle's experimental browser. It has an underestimated potential. Will keep an eye on this, even if am now using a Kobo H20.
- geniium 10y ago
  Update: the conclusion of the article mentioned : "For the fix, Amazon did quite a few things. They sandboxed the browser, fixed the permissions issue, removed fc-cache.sh, and most likely patched Webkit. Webkit still crashes when executing the PoC. Unsure if that's because of the process running out of memory or some other issue."
shostack 10y ago
All I want is to invert colors on my Paperwhite for easier reading with the lights off. Why is that so hard?

306 points by bdelay 10y ago

Could anyone knowledgeable about this explain what you can do with a jailbroken kindle that you cannot do with a locked one?

joezydeco 10y ago
You mean besides what was mentioned in the article?
- jonahx 10y ago
  Afaict, it's entirely a technical writeup about how to jailbreak. From the intro: "This document details the steps and thought processes I went through when developing the jailbreak. Ideally this will be a useful map or starting point for anyone looking at the system in the future". I didn't find any information aimed at users of the Kindle about why they'd want to jailbreak.
  - jasode 10y ago
    I assume gp was talking about the 7th paragraph mentioning "whys" such as epub, fonts, screensavers: >The mobileread community has done a great job developing extended functionality of the readers. Some of the more popular packages involve an open-source alternative reader with ePub support, a plugin to change fonts, and another addon to enable custom screensaver images.
replax 10y ago
Well, the kindle runs essentially Linux so by jailbreaking it you gain the ability to launch arbitrary code! Eg alternate pdf readers, games, ssh, vim and a lot more which can be very useful (especially the off reader KOreader)! check out mobilereads forums if you want to know more about that, it's a vibrant community.
- dharma1 10y ago
  Is it usable in a beach situation, if you really need to hack away in bright sunshine?
  - emodendroket 10y ago
    This is precisely the scenario e-ink excels in.
  - lj3 10y ago
    This guy thinks so: https://tinyapps.org/docs/e-ink-monitor.html https://tinyapps.org/docs/e-ink-monitor.html
    - dharma1 10y ago
      Nice. I wonder if you could do away with the laptop altogether, and just use your phone with the Kindle, maybe with a bluetooth keyboard for the kindle (for some light work on a beach). Or if there are any other e-ink tablets that run a full linux (cli) or Android?
      - lj3 10y ago
        There are eink readers that are easier to hack, like the Kobo, but they're all limited in that they're e-readers and have the minimal processing power to match. The only full on eink tablet I know of is this one[0] which technically doesn't exist yet. It's fully funded, though, so I'm excited to see if it actually ships. [0]: https://www.indiegogo.com/projects/13-3-inch-android-e-reader#/ https://www.indiegogo.com/projects/13-3-inch-android-e-reade...
        dharma1 10y ago
        That 13.3 e-ink tablet looks pretty tasty, I hope it materialises. I suppose you could run VNC on your Android/Ubuntu phone, and just use the e-ink tablet as a thin client. Maybe the slow redraw of e-ink would suck for real work, unless there are ways to make it more palatable for terminal work
deleted 10y ago
[deleted]
rmi_ 10y ago
Probabaly remove the ads from the subsidised version.
- ArtDev 10y ago
  This part is easy. Just remove/replace the ad images and keep it on airplane mode. I still plan to jailbrake when I get around to it
gadders 10y ago
Not related to this hack, but I did see a post from a guy once that hacked his girlfriend's kindle so the screen saver showed the cover of "Mein Kampf" as a prank.
zyxley 10y ago
What I'd really like to see, personally, is Dropbox syncing over wifi with an arbitrary library of ebooks.
- semi-extrinsic 10y ago
  On stock (and jailbroken) Kindles you can send PDFs or MOBIs to username@kindle.com and have them auto-downloaded to your Kindle. Many people use Calibre[1] (FOSS, win/mac/linux) to sync/manage their ebook collection using this feature. You could easily couple it with Dropbox. You can also use Calibre to have newspapers/magazines sent to your Kindle every morning. There's tons of recipes for scraping BBC, NYTimes, WaPo or $local_paper, rendering with custom CSS to get readable ad-free version, converting to MOBI and sending to Kindle. There has even been SaaS offerings running hosted Calibre cronjobs with user-provided recipes. Not sure if any still exist. [1] https://calibre-ebook.com https://calibre-ebook.com
  - zyxley 10y ago
    > On stock (and jailbroken) Kindles you can send PDFs or MOBIs to username@kindle.com and have them auto-downloaded to your Kindle. That's no good for me because I tend to do a lot of random edits of my epub collection to fix editing errors, replace cover images with better ones, etc. The reason I want Dropbox is to automatically propagate changes like that, not just to transfer files over.
    - semi-extrinsic 10y ago
      Upstream comment recommends running KOreader on jailbroken Kindle for (amongst other things) syncing with Calibre. I'm assuming this is two-way sync, but I don't know.
semi-extrinsic 10y ago
I've jailbroken mine to have custom covers. Instead of famous dead American authors I've never read, I have famous dead physicists whom I've actually read and whom I admire.
- chadgeidel 10y ago
  I'd love to do this using "pulp" science fiction book covers. I assumed that there was already a tutorial for this, but my Google-fu is weak. Did you use a guide or just DIY? What size/resolution image does the Kindle expect? Is there a filename format or a directory structure to use?
  - semi-extrinsic 10y ago
    Here you go (there is a link on that page for latest Kindle's, this is for v. 1/2/3/4: http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for_all_2.x,_3.x_%26_4.x_Kindles http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for... Image format is grayscale 800x600 (bigger for Kindle DX) png or jpg. For best quality I recommend fiddling a bit with the color to grayscale work in Gimp or Photoshop, especially if the image has large areas with soft gradients. IIRC, running a selective Gaussian blur after grayscaling, and/or working the curves tool a bit before grayscaling, will improve problematic images quite a bit. Early models had only 4 grayscales, now they have 16. "Posterize" to 4 or 16 colors after grayscale in Gimp will give you a good idea of how the end result looks.
  - DanBC 10y ago
    I think you want screensaver hacks. Here's one example, but there are others. http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for_all_2.x,_3.x_%26_4.x_Kindles http://wiki.mobileread.com/wiki/Kindle_Screen_Saver_Hack_for... Some people add their contact details to the screensaver images, so if you lose your kindle your contact details are the first thing someone who finds it will see.
    - rsync 10y ago
      Maybe a better hack would be to disable screensavers since they serve no purpose on an e-paper display and actually cost battery to switch from text -> screensaver -> text. The better behavior would be to not flip the screen at all and keep it static, using no battery.
bdelay 10y ago
As mentioned, I think the most popular use is for custom covers. Recent firmware versions show that Amazon might be slowly working towards this as a feature. As the guy who wrote this, I don't use any of the addons. Just did it for fun.
ptero 10y ago
I like to be able to read books in other formats (FB2 is a prime example) and use custom readers (e.g., I like coolreader for its configurability). I think neither is an option with Kindle, so I use a rooted Nook. However, I like Kindle hardware a bit more, so I would probably switch if it can be unstuck from using the Amazon default software choices.
rwmj 10y ago
I turned mine into a little status display, showing today's weather (and a few other geeky things, but that's the main one). The combination of very low power usage and readable e-Ink display is great. Also older models are very cheap -- mine was £50 including delivery. You can find tutorials for doing this all over the place, eg https://www.youtube.com/watch?v=Oel08SDFyIY https://www.youtube.com/watch?v=Oel08SDFyIY (not the particular one I used, but he's done a very similar job to mine).
Applejinx 10y ago
I can tell you what I'd like to do with my Kindle, that's absolutely worth jailbreaking it. I use it for my own .mobi files from a variety of sources, including books I wrote myself. I purchased mine and paid to have no advertising on it. I would roll back to the previous operating system, which did not have advertisements on the homescreen and did not make me navigate two levels deep just to get past subfolders and a 'downloaded' option hiding my own books from me by default, and I would remove its ability to update itself or do anything via wi-fi. I would just connect it via USB for all file management, and that would be perfect for me. Needless to say, I'm really frustrated with the 'update' I never asked for OR installed, which has screwed up these things. I am very, very interested in what can be done with this jailbreaking. All the more as I don't wish ever to purchase a book through Amazon again, if this is the direction they're going. And they are, they obviously are.
- int_19h 10y ago
  One nifty trick that I found few people know about, is that you can upload your own .mobi books into the Kindle cloud. Just use the email that they provide to upload PDFs and the like. Once the books are there, they show in your cloud collection and are available for download, same as Amazon-purchased books. Better yet, you will also get cloud sync across devices for current location, bookmarks etc - probably the most enticing reason to go down this route. (Not sure if this is helpful to you, if you really prefer to manage files directly via USB. But might be helpful to someone else.)
- S4M 10y ago
  The first thing I did was to turn off the wifi on my kindle, so I don't have to deal with upgrades or ads. And somehow I can add my own .mobi file to my kindle via usb. I added pdfs I converted to .mobi that way (with some software I found through a google search).
- dublinben 10y ago
  It sounds like you should just buy a different e-reader then. The kindle is not the right product for you.
cpayne 10y ago
I was thinking the same thing... I can only think of "bragging rights" or a learning experience. Although I think this is what makes the (internet) world awesome at the moment. The author sounds like they were mucking around to see how far they could get. Put some thoughts down for others to read and who knows? Whenever we're recruiting, we always look for interesting things a candidate has done. Something like this will easily get you a first interview...

Zombieball 10y ago

Not sure if you are the author or just sharing. If you authored this I would highly recommend mentioning which "kindle" this is applicable to as the first topic. There are multiple generations of kindle e-readers and kindle tablets. It's not readily apparent up front as to which this is applicable to.

SippinLean 10y ago
>every Kindle with a 5.6.5 firmware release
- softawre 10y ago
  You may want to mention what firmware version.
dflock 10y ago
> At the time, the jailbreak opened up every Kindle with a 5.6.5 firmware release.
- deleted 10y ago
  [deleted]
takeda 10y ago
The first paragraph says "This is a write-up on the development of the Kindle 5.6.5 Webkit based jailbreak released in February 2016. At the time, the jailbreak opened up every Kindle with a 5.6.5 firmware release."
- Zombieball 10y ago
  I read this. Which meant nothing to me. Kindle e-reader? Do all e-readers have the same OS? Granted I may not be the target audience. Presumably some one looking to jailbreak their e-reader may have recognized this right off the bat. As someone who recently purchased a cheap kindle fire tablet, and was interested in the possibility of jail breaking, I was confused. Edit: great post though! I researched previously in jail breaking kindle e-readers with not so much luck. Ever since I saw AWS use them as displays for snowball devices I started to see potential for other uses. Will have to try this out.

david-given 10y ago

I did some playing with a Kindle 3 a few years back --- I was writing programs that integrated into the native UI. I built an app which was a Javascript interpreter bolted onto a VT52 terminal emulator. You could type in programs and run them! Using the K3's fiddly little keyboard! Um, awesome. http://cowlark.com/kindle/javascript.html http://cowlark.com/kindle/javascript.html This was on the 3.1 firmware, so it's likely all completely obsolete on modern devices. ...the 3.1 firmware was terrible. It was all Java based, but Java 1.4. No generics! No autoboxing! No foreach! People forget just how awful early versions of Java were in comparison to what we have today. I ended up building a toolchain using RetroWeaver to convert modern Java bytecode into something that would run on the Kindle. Also, the firmware was based on the Personal Basis Profile 1.1. Think back, way into the past, before there were smartphones and Android and iOS... back to the heyday of the downloadable Java applet for your T9-based phone. Yup, that. Kindle apps were midlets, and anyone who remembers writing programs for midlets will be shuddering by now. And it gets worse! The Kindle ran the entire UI, third-party applications included, in a single Java VM. It was as fragile as hell, and it tended to silt up with un-garbagecollectable data until it crashed and rebooted. If you left a thread running on application exit, it would crash and reboot. If your app hung you had to power cycle the device. I believe that the reason why Amazon never really opened up the Kindle to large-scale third party apps was mainly embarrassment. Good times. Good times...

esrauch 10y ago
I was an intern on a team that did some Kindle work in 2010 and the Java limitations at that time were definitely a very real annoyance for internal code: they didn't do anything like you are describing for Java bytecode conversion for 1p development to make it less annoying. The issue was maybe even deeper than you noticed, core parts of the API like String.substring() weren't implemented and would just throw a runtime exception.
- david-given 10y ago
  You mean... you wrote Java 1.4 by hand? I'm so, so sorry.
10y ago

mintplant 10y ago

I wouldn't use my Kindle half as much if it weren't for KOReader [0]. Ironically enough for a dedicated reading device, Amazon's built-in reader app pales in comparison to this third-party tool. The killer feature for me is on-the-fly column splitting and text reflow, with the ability to flip to the original page view by tapping a corner -- this is critical for reading academic papers, which tend to be two-column PDFs. It also features contrast adjustment, more fonts, stylesheets, wireless syncing with Calibre, and support for many more file formats including ePub. There's also a Gargoyle [1] port for interactive fiction on the go. It's less practical due to the input lag on the Kindle keyboard, but I still pull it out every now and again. [0] https://github.com/koreader/koreader https://github.com/koreader/koreader [1] http://www.fabiszewski.net/kindle-gargoyle/ http://www.fabiszewski.net/kindle-gargoyle/

josteink 10y ago
> - this is critical for reading academic papers, which tend to be two-column PDFs Kindle's and PDFs goes together badly. This is common knowledge. My solution is only using web-pages based formats like mobi or epub based books. The rest... Let's say they don't get in my reading list. Just like the web is nicer without flash, ebooks are just nicer without publishing formats like PDFs which natively can't support reflow or anything super basic required for easy reading.
- deleted 10y ago
  [deleted]
- throwawayIndian 10y ago
  > Just like the web is nicer without flash, ebooks are just nicer without publishing formats like PDFs. Web is nice because of flash. The video tag in HTML5 happened only after successes of services like Youtube and Vimeo and hundreds of others after they set off on their paths with Macromedia flash. Stop fooling yourself with that kool-aid against flash in recent years. It's dated for sure, but credit be given where credit is due.
  - 10y ago

criddell 10y ago

All I want is an e-ink device that I can use with books purchased from Amazon, Apple, Google, B&N, and other vendors. Why is that so hard?

cheeze 10y ago
$$$
ArtDev 10y ago
Check out the Kobo.
- criddell 10y ago
  I have. Last time I checked, the Kobo couldn't open DRM protected books from Amazon.
  - dublinben 10y ago
    It can if you remove the DRM from them. Amazon is selling you a broken product, so I don't recommend buying books from them anyway.
    - criddell 10y ago
      True, but I wouldn't care about DRM if I could still buy books at any bookstore. DVD's and Blueray disks have DRM, but I can buy one from any store and it will work with my player and my TV. It doesn't seem like a lot to ask for.

enthdegree 10y ago

How do you get the background to pursue this sort of thing? I've programmed and used Linux for a little while and I've done some simple things in assembly language (although not in much depth), but all the technical things past the CVE-2013-2842 section are impenetrable to me.

bdelay 10y ago
Started out cracking software on embedded systems a long time ago. That led to an understanding of ASM and reverse engineering. Going from there to exploitation isn't a giant leap. There's quite a few books on the subject. Hacking: The Art of Exploitation is a decent hello world introduction to the subject. Reading CTF practice problem writeups and then trying easier ones yourself are also good experiences. For REing, http://crackmes.de http://crackmes.de is a blast. The entry level challenges should be easy to grasp after reading a few tutorials. Would recommend running everything in a Windows VM. ;) Good luck!

Steeeve 10y ago

The more I see writeups like this, the more I wonder if the effort being laid out by the people doing the work is compensated appropriately. I'm not sure what Amazon pays for identifying a security flaw, but I imagine it's somewhere between $5 and $15k. Having success monthly might yield reasonable compensation, but companies only pay when a flaw is identified, which means you don't get paid for your work, you get paid for your successful work. And you don't get to define what is successful, nor is there usually a clear definition of what successful actually means. I understand that many people do this to get a job in security / security research, but it just seems like the effort-to-payoff ratio still favors people using their found exploits for evil dramatically. There really should be a different pricing model around security exploits - one that encourages responsible disclosure more heavily.

bdelay 10y ago
I don't believe Amazon officially pays for security flaws. They ended up sending me a free Kindle (pretty funny) and got an interview out of it. That didn't end up going anywhere, but I got a heck of a lot further than the black hole that is most job application processes these days. Seemed like a fair trade considering the market for Kindle 0days is somewhere near $0. It's a neat project to talk about during interviews. Nothing more.

Steeeve 10y ago

pavanlimo 10y ago

I was recently researching ebook readers and found Kobo devices way better than Kindle (and cheaper too). Especially for somebody who is a power user of devices. Without getting into specifities, I found that in general Kobo is more open.

wineisfine 10y ago

Btw here is a webservice that converts and sends ePub's to your kindle, without having to use Calibre yourself http://www.sendepubtokindle.com http://www.sendepubtokindle.com

geniium 10y ago

Maybe that'll make Amazon update their Kindle's experimental browser. It has an underestimated potential. Will keep an eye on this, even if am now using a Kobo H20.

geniium 10y ago
Update: the conclusion of the article mentioned : "For the fix, Amazon did quite a few things. They sandboxed the browser, fixed the permissions issue, removed fc-cache.sh, and most likely patched Webkit. Webkit still crashes when executing the PoC. Unsure if that's because of the process running out of memory or some other issue."

shostack 10y ago

All I want is to invert colors on my Paperwhite for easier reading with the lights off. Why is that so hard?