29 ms·

Geedge and MESA leak: Analyzing the great firewall’s largest document leak

438 points by yourapostasy 1y ago

https://www.tomshardware.com/tech-industry/chinas-great-firewall-springs-huge-leak https://www.tomshardware.com/tech-industry/chinas-great-fire... https://x.com/gfw_report/status/1966669581302309018 https://x.com/gfw_report/status/1966669581302309018

sciencesama 1y ago
All i need is a simple firewall to block advertisements
academicfish 1y ago
I wonder who's the Chinese Snowden behind the leak.
- szundi 1y ago
  Yes … while hoping no one ever finds out
- ragnot 1y ago
  Probably some guy called (C)hen (I)ao (A)n
  - lpribis 1y ago
    If it was a three letter agency, surely they have little motivation to leak it publicly? I feel it would be more strategic for them to keep the information to themselves since presumably no one outside of GFW development knows the exact details (until now).
    - ragnot 1y ago
      > The Great Firewall of China (GFW) experienced the largest leak of internal documents in its history on Thursday September 11, 2025. Ironic that this happens on 9/11 of all days right?
wartywhoa23 1y ago
This whole discussion is full of devil's advocates. The society is fucked
- bt1a 1y ago
  Lolz
honeybadger1 1y ago
there is a controlled effort for this type of apparatus to exist everywhere
- integricho 1y ago
  Suddenly all leaders are wannabe autocrats, even the great western democratic ones, they just like to pretend about still caring about democracy.
  - noarchy 1y ago
    You could argue that some of them aren't bothering to pretend at this point.
  - Havoc 1y ago
    It’s not particularly sudden - we in the west just perceive it as such thanks to recent drama. Majority of the world population wasn’t living in a democracy for a while now (not even sure it ever has)
razighter777 1y ago
When a government feels the need to implement technical control measures against ordinary citizens, the tight leash that the people had on their government's authority is broken. Mass censorship, surviellence, and erosion of privacy are incompatible with human dignity. Purely utilitarian stances advocating online censorship "for the greater good", exploiting the causes of "terrorism" and "child safety" fail to consider anything more than the first order consequences. Once a government taste the powerful liquor of censorship, there's no way that bottle's ever getting corked again. You bet your ass when anything happens that threatens those in power, that they'll be using that censorship on more than just the evil porn websites and terrorists. I hope that this GFW leak helps researchers and hobbyists alike find more ways to fight against government erosion of personal dignity.
- logicchains 1y ago
  >Once a government taste the powerful liquor of censorship, there's no way that bottle's ever getting corked again. Seems the youth of Nepal managed to cork the bottle again earlier this month, when after the mass social media ban they burned down the government buildings and chased the parliamentarians out of the country.
  - 1oooqooq 1y ago
    same won't happen on russia or usa. if musk "buys" trump's untruth network and merge it with the remains or xitter, and then all the others are blocked to "save the children" nobody will say anything. maybe, just maybe, there will be a stockholders lawsuit on meta for the value dropping to zero. but hardly anything else.
    - hellojesus 1y ago
      Users can stop using it. Good luck to the gov banning any and all sites. People will migrate to drcentralized networks or deep web areas.
      - grim_io 1y ago
Hizonner 1y ago
Gotta wonder what kind of failed excuse for a human being you have to be to devote your talents to building stuff like that...
- bschwindHN 1y ago
  If you can make money from it, there will always be someone willing to do it. And/or there is always someone you can compel to do it. It sucks but you pretty much have to operate with that assumption for most things.
  - erikpukinskis 1y ago
    Yes, but if you turn down the opportunity, statistically the person who takes it will be slightly worse at their job than you would have been. If enough people apply some ethical line, it creates a genuine headwind for evildoers.
    - lossolo 1y ago
      That's wishful thinking. If you pay enough, you will find talent without any problems in this world. Look at all the sophisticated zero day exploits used against journalist.
- tga_d 1y ago
  There's a sort of mirror world of academic research happening, where on one side of the mirror, you have people building the tools to censor the internet (typically but not always in Asian venues), and on the other, the tools to circumvent that censorship (typically but not always in Western venues). I know far more people on the latter half of the equation, but have enough exposure to the other side of the mirror to know that most of them earnestly believe they're doing something good. They see massive megacorportaions pushing American interests as an unfair lever in a fight for national sovereignty, and what they do as simply leveling the playing field, and combating misinformation. While I would wholeheartedly agree that they are mistaken in their analysis (reifying systems for people, "The institution I'm supporting may sometimes do bad things, but what I do is supporting the good parts!") and should immediately stop, I wouldn't want to dehumanize them any more than I would someone who works for Palantir, or even Google, Amazon, etc.
DrWhax 1y ago
We at Amnesty looked at how the authorities there deployed it in Pakistan: https://www.amnesty.org/en/latest/news/2025/09/pakistan-mass-surveillance-and-censorship-machine-is-fueled-by-chinese-european-emirati-and-north-american-companies/ https://www.amnesty.org/en/latest/news/2025/09/pakistan-mass...
miohtama 1y ago
Some analysis and discussion here: https://github.com/net4people/bbs/issues/519 https://github.com/net4people/bbs/issues/519 > After its founding in 2018, one of Geedge's first clients was the government of Kazakhstan, to whom the company sold its flagship Tiangou Secure Gateway (TSG), which provides functions similar to China's own Great Firewall, monitoring and filtering all web traffic that passes through it, as well as attempts to bypass such censorship. > The same tool has been rolled out in Ethiopia and Myanmar, where it has been instrumental in enabling that country's military junta to enforce a ban on VPNs. In many cases, Geedge works with other private companies, including internet service providers (ISPs) such as Safaricom in Ethiopia, or Frontiir and Ooredoo in Myanmar, to enact government censorship, the documents show. No ISPs that have partnered with Geedge responded to a request for comment. > The leaks show employees at the company working to reverse-engineer many popular tools and find means of blocking them. One set of documents lists nine commercial VPNs as "resolved," and provides various means of identifying and filtering traffic to them. Similar capabilities have long been demonstrated by the Great Firewall, with most commercial VPNs inaccessible from within China and many dedicated anti-censorship tools also hard to access. > At least one Jira support ticket shows evidence of plaintext capture of email
- MangoToupe 1y ago
  > At least one Jira support ticket shows evidence of plaintext capture of email I would be surprised if western governments didn't do the same, and folks should act accordingly.
  - nilamo 1y ago
    We don't need to guess, we know they do. That was one of Snowden's big reveals.
  - oogali 1y ago
    The US has been doing this for a long time (1997), on a targeted basis. https://en.wikipedia.org/wiki/Carnivore_(software) https://en.wikipedia.org/wiki/Carnivore_(software)
  - perihelions 1y ago
FridayoLeary 1y ago
My first thought was unfortunately whether the UK and other Western nations would copy this to build their own Firewalls. To be honest i still don't think it's a goal anyone is actively working towards and that's a bit of an hyperbolic take. But the truth is that we are moving more towards such a system then we are moving away. My second thought is how badly Chinese communism must be doing that they need such a massive effort in order to prevent their citizens from accessing information and voicing dissent. We are lucky to be living in such a free society. Internet seems to be losing the battle against government interference and censorship and that is more of a bad thing then a good thing.
- deleted 1y ago
  [deleted]
- wartywhoa23 1y ago
  > i still don't think it's a goal anyone is actively working towards and that's a bit of an hyperbolic take now this is what Pink Floyd meant by "comfortably numb". mass cognitive dissonance and denial
- MangoToupe 1y ago
  > My second thought is how badly Chinese communism must be doing that they need such a massive effort in order to prevent their citizens from accessing information and voicing dissent. I don't quite understand why the first impulse is that it covers up government incompetence. There are other incentives for mass social control of discourse and information.
- hujun 1y ago
  "My second thought is how badly Chinese communism must be doing that they need such a massive effort in order to ..." China have visa-free visit policy for many countries, you could actually go there to see how "bad" it is https://www.china-briefing.com/news/china-visa-free-travel-policies-complete-guide/ https://www.china-briefing.com/news/china-visa-free-travel-p...
  - rangestransform 1y ago
nromiun 1y ago
AFAIK QUIC traffic is impossible to attack using MITM techniques. So I wonder how the GFW handles it. Do they block it entirely or still filter it somehow?
- jeroenhd 1y ago
  You don't need QUIC, TLS and other encrypted channels have the same protection. It's not hard to identify those channels and block them. A connection used to interact with websites has completely different traffic patterns compared to a user sending all of their traffic over one specific connection. Add to that the fact that large video streaming services such as YouTube, where you may see large quantities of data being exchanged over persistent connections, are already blocked in China, and your VPN becomes quite obvious without seeing even a byte of plaintext. Of course for common protocols like QUIC they have their own custom solution (linked in a sibling comment), but the point is that even with encrypted SNI you will need dedicated anti-GFW protocols to stand a chance against censorship. No protocol that works well for most consumers is going to protect against the analysis a dedicated firewall with decent funding can come up with.
- immibis 1y ago
  Typically they rely on metadata like the IP you're connecting to, or downgrade attacks. Until every server supports QUIC they can just pretend the server doesn't support QUIC. You might think IP checks are safe because everything's on Cloudflare and they can't block Cloudflare, but you'd be wrong. Even Spain blocks Cloudflare (yes, entirely) during football games.
- xyzzy123 1y ago
  According to https://gfw.report/publications/usenixsecurity25/en/#3 https://gfw.report/publications/usenixsecurity25/en/#3 they sniff the SNI out of the handshake like for TLS.
  - 3abiton 1y ago
    Is that a new technique? Shouldn't this be mitigated?
hks0 1y ago
I used to live in a country who is also a customer of GFW. Before v2ray came out, I had figured out devising any random protocol would defeat it. I would pass my SSH connecting used for socks5 through ROT13 or any ROTn, then the firewall won't gradually slow it down towards total stall after a few kilobytes. OpenSSH yells its name and version in plain text upon connection. A few years later (still before v2ray) they got more aggressive: Unknown protocols were stalled after a few kilobytes. I then learned if I pretend I'm doing something legitimate (!) such as downloading favicon.ico within a proper HTTP channel, they won't touch my "packets" (the favicon content was my packet). I think there was also a Iodine project doing the same with ping packets but it was slower than favicon-as-packets for me. Today I see v2ray has taken it to the maximum extent, suggesting valid web page front for an IP, valid https certificates, etc. When I started making money I was thinking about renting many IPs and send my traffic as round-robin to them as the detection relied heavily on IP consistency. That is, connections were fingerprinted by IP. I don't live there anymore and don't get to verify this hypothesis, but given the leaked source codes it's an intersting weekend project. What else is also interesting, I looked at traffic decoders in the list of leaked source files: TCP, HTTP, QUIC, ... but no mention of UDP, which made no difference in bypassing GFW. I guess the same IP rate limiter was at work with UDP at a lower level.
- hiddendoom45 1y ago
  From my own personal experience with an outline server running on the same IP over 3 years, the GFW consistently ends up blocking it around 3 days after I first connect. Outline does use shadowsocks to obfuscate but I suspect the traffic detection is what triggers it after 3 days of observations. Running multiple servers and repeatedly cycling through them is an experiment I want to try the next time I'm there. I've also observed similar behavior with the vpn I'm using as backup where the server I'm using tends to get blocked in around the same timeframe. It's using openvpn/wireguard as the underlying protocol which doesn't try to obfuscate itself so I suspect traffic pattern analysis plays a larger role in what gets blocked than the protocol itself. The exception was my recent trip week-long trip where I was mostly cycling between two servers without noticing either being blocked.
  - 1y ago
smoovb 1y ago
Interesting, a apparent GFW insider (GFW官方代表) making a statement on the leak and its source: https://github.com/net4people/bbs/issues/519#issuecomment-3300358468 https://github.com/net4people/bbs/issues/519#issuecomment-33...

438 points by yourapostasy 1y ago

sciencesama 1y ago

All i need is a simple firewall to block advertisements

academicfish 1y ago

I wonder who's the Chinese Snowden behind the leak.

szundi 1y ago
Yes … while hoping no one ever finds out
ragnot 1y ago
Probably some guy called (C)hen (I)ao (A)n
- lpribis 1y ago
  If it was a three letter agency, surely they have little motivation to leak it publicly? I feel it would be more strategic for them to keep the information to themselves since presumably no one outside of GFW development knows the exact details (until now).
  - ragnot 1y ago
    > The Great Firewall of China (GFW) experienced the largest leak of internal documents in its history on Thursday September 11, 2025. Ironic that this happens on 9/11 of all days right?

wartywhoa23 1y ago

This whole discussion is full of devil's advocates. The society is fucked

bt1a 1y ago
Lolz

honeybadger1 1y ago

there is a controlled effort for this type of apparatus to exist everywhere

integricho 1y ago
Suddenly all leaders are wannabe autocrats, even the great western democratic ones, they just like to pretend about still caring about democracy.
- noarchy 1y ago
  You could argue that some of them aren't bothering to pretend at this point.
- Havoc 1y ago
  It’s not particularly sudden - we in the west just perceive it as such thanks to recent drama. Majority of the world population wasn’t living in a democracy for a while now (not even sure it ever has)

razighter777 1y ago

When a government feels the need to implement technical control measures against ordinary citizens, the tight leash that the people had on their government's authority is broken. Mass censorship, surviellence, and erosion of privacy are incompatible with human dignity. Purely utilitarian stances advocating online censorship "for the greater good", exploiting the causes of "terrorism" and "child safety" fail to consider anything more than the first order consequences. Once a government taste the powerful liquor of censorship, there's no way that bottle's ever getting corked again. You bet your ass when anything happens that threatens those in power, that they'll be using that censorship on more than just the evil porn websites and terrorists. I hope that this GFW leak helps researchers and hobbyists alike find more ways to fight against government erosion of personal dignity.

logicchains 1y ago
>Once a government taste the powerful liquor of censorship, there's no way that bottle's ever getting corked again. Seems the youth of Nepal managed to cork the bottle again earlier this month, when after the mass social media ban they burned down the government buildings and chased the parliamentarians out of the country.
- 1oooqooq 1y ago
  same won't happen on russia or usa. if musk "buys" trump's untruth network and merge it with the remains or xitter, and then all the others are blocked to "save the children" nobody will say anything. maybe, just maybe, there will be a stockholders lawsuit on meta for the value dropping to zero. but hardly anything else.
  - hellojesus 1y ago
    Users can stop using it. Good luck to the gov banning any and all sites. People will migrate to drcentralized networks or deep web areas.
    - grim_io 1y ago

Hizonner 1y ago

Gotta wonder what kind of failed excuse for a human being you have to be to devote your talents to building stuff like that...

bschwindHN 1y ago
If you can make money from it, there will always be someone willing to do it. And/or there is always someone you can compel to do it. It sucks but you pretty much have to operate with that assumption for most things.
- erikpukinskis 1y ago
  Yes, but if you turn down the opportunity, statistically the person who takes it will be slightly worse at their job than you would have been. If enough people apply some ethical line, it creates a genuine headwind for evildoers.
  - lossolo 1y ago
    That's wishful thinking. If you pay enough, you will find talent without any problems in this world. Look at all the sophisticated zero day exploits used against journalist.
tga_d 1y ago
There's a sort of mirror world of academic research happening, where on one side of the mirror, you have people building the tools to censor the internet (typically but not always in Asian venues), and on the other, the tools to circumvent that censorship (typically but not always in Western venues). I know far more people on the latter half of the equation, but have enough exposure to the other side of the mirror to know that most of them earnestly believe they're doing something good. They see massive megacorportaions pushing American interests as an unfair lever in a fight for national sovereignty, and what they do as simply leveling the playing field, and combating misinformation. While I would wholeheartedly agree that they are mistaken in their analysis (reifying systems for people, "The institution I'm supporting may sometimes do bad things, but what I do is supporting the good parts!") and should immediately stop, I wouldn't want to dehumanize them any more than I would someone who works for Palantir, or even Google, Amazon, etc.

DrWhax 1y ago

We at Amnesty looked at how the authorities there deployed it in Pakistan: https://www.amnesty.org/en/latest/news/2025/09/pakistan-mass-surveillance-and-censorship-machine-is-fueled-by-chinese-european-emirati-and-north-american-companies/ https://www.amnesty.org/en/latest/news/2025/09/pakistan-mass...

miohtama 1y ago

Some analysis and discussion here: https://github.com/net4people/bbs/issues/519 https://github.com/net4people/bbs/issues/519 > After its founding in 2018, one of Geedge's first clients was the government of Kazakhstan, to whom the company sold its flagship Tiangou Secure Gateway (TSG), which provides functions similar to China's own Great Firewall, monitoring and filtering all web traffic that passes through it, as well as attempts to bypass such censorship. > The same tool has been rolled out in Ethiopia and Myanmar, where it has been instrumental in enabling that country's military junta to enforce a ban on VPNs. In many cases, Geedge works with other private companies, including internet service providers (ISPs) such as Safaricom in Ethiopia, or Frontiir and Ooredoo in Myanmar, to enact government censorship, the documents show. No ISPs that have partnered with Geedge responded to a request for comment. > The leaks show employees at the company working to reverse-engineer many popular tools and find means of blocking them. One set of documents lists nine commercial VPNs as "resolved," and provides various means of identifying and filtering traffic to them. Similar capabilities have long been demonstrated by the Great Firewall, with most commercial VPNs inaccessible from within China and many dedicated anti-censorship tools also hard to access. > At least one Jira support ticket shows evidence of plaintext capture of email

MangoToupe 1y ago
> At least one Jira support ticket shows evidence of plaintext capture of email I would be surprised if western governments didn't do the same, and folks should act accordingly.
- nilamo 1y ago
  We don't need to guess, we know they do. That was one of Snowden's big reveals.
- oogali 1y ago
  The US has been doing this for a long time (1997), on a targeted basis. https://en.wikipedia.org/wiki/Carnivore_(software) https://en.wikipedia.org/wiki/Carnivore_(software)
- perihelions 1y ago

FridayoLeary 1y ago

My first thought was unfortunately whether the UK and other Western nations would copy this to build their own Firewalls. To be honest i still don't think it's a goal anyone is actively working towards and that's a bit of an hyperbolic take. But the truth is that we are moving more towards such a system then we are moving away. My second thought is how badly Chinese communism must be doing that they need such a massive effort in order to prevent their citizens from accessing information and voicing dissent. We are lucky to be living in such a free society. Internet seems to be losing the battle against government interference and censorship and that is more of a bad thing then a good thing.

deleted 1y ago
[deleted]
wartywhoa23 1y ago
> i still don't think it's a goal anyone is actively working towards and that's a bit of an hyperbolic take now this is what Pink Floyd meant by "comfortably numb". mass cognitive dissonance and denial
MangoToupe 1y ago
> My second thought is how badly Chinese communism must be doing that they need such a massive effort in order to prevent their citizens from accessing information and voicing dissent. I don't quite understand why the first impulse is that it covers up government incompetence. There are other incentives for mass social control of discourse and information.
hujun 1y ago
"My second thought is how badly Chinese communism must be doing that they need such a massive effort in order to ..." China have visa-free visit policy for many countries, you could actually go there to see how "bad" it is https://www.china-briefing.com/news/china-visa-free-travel-policies-complete-guide/ https://www.china-briefing.com/news/china-visa-free-travel-p...
- rangestransform 1y ago

nromiun 1y ago

AFAIK QUIC traffic is impossible to attack using MITM techniques. So I wonder how the GFW handles it. Do they block it entirely or still filter it somehow?

jeroenhd 1y ago
You don't need QUIC, TLS and other encrypted channels have the same protection. It's not hard to identify those channels and block them. A connection used to interact with websites has completely different traffic patterns compared to a user sending all of their traffic over one specific connection. Add to that the fact that large video streaming services such as YouTube, where you may see large quantities of data being exchanged over persistent connections, are already blocked in China, and your VPN becomes quite obvious without seeing even a byte of plaintext. Of course for common protocols like QUIC they have their own custom solution (linked in a sibling comment), but the point is that even with encrypted SNI you will need dedicated anti-GFW protocols to stand a chance against censorship. No protocol that works well for most consumers is going to protect against the analysis a dedicated firewall with decent funding can come up with.
immibis 1y ago
Typically they rely on metadata like the IP you're connecting to, or downgrade attacks. Until every server supports QUIC they can just pretend the server doesn't support QUIC. You might think IP checks are safe because everything's on Cloudflare and they can't block Cloudflare, but you'd be wrong. Even Spain blocks Cloudflare (yes, entirely) during football games.
xyzzy123 1y ago
According to https://gfw.report/publications/usenixsecurity25/en/#3 https://gfw.report/publications/usenixsecurity25/en/#3 they sniff the SNI out of the handshake like for TLS.
- 3abiton 1y ago
  Is that a new technique? Shouldn't this be mitigated?

hks0 1y ago

I used to live in a country who is also a customer of GFW. Before v2ray came out, I had figured out devising any random protocol would defeat it. I would pass my SSH connecting used for socks5 through ROT13 or any ROTn, then the firewall won't gradually slow it down towards total stall after a few kilobytes. OpenSSH yells its name and version in plain text upon connection. A few years later (still before v2ray) they got more aggressive: Unknown protocols were stalled after a few kilobytes. I then learned if I pretend I'm doing something legitimate (!) such as downloading favicon.ico within a proper HTTP channel, they won't touch my "packets" (the favicon content was my packet). I think there was also a Iodine project doing the same with ping packets but it was slower than favicon-as-packets for me. Today I see v2ray has taken it to the maximum extent, suggesting valid web page front for an IP, valid https certificates, etc. When I started making money I was thinking about renting many IPs and send my traffic as round-robin to them as the detection relied heavily on IP consistency. That is, connections were fingerprinted by IP. I don't live there anymore and don't get to verify this hypothesis, but given the leaked source codes it's an intersting weekend project. What else is also interesting, I looked at traffic decoders in the list of leaked source files: TCP, HTTP, QUIC, ... but no mention of UDP, which made no difference in bypassing GFW. I guess the same IP rate limiter was at work with UDP at a lower level.

hiddendoom45 1y ago
From my own personal experience with an outline server running on the same IP over 3 years, the GFW consistently ends up blocking it around 3 days after I first connect. Outline does use shadowsocks to obfuscate but I suspect the traffic detection is what triggers it after 3 days of observations. Running multiple servers and repeatedly cycling through them is an experiment I want to try the next time I'm there. I've also observed similar behavior with the vpn I'm using as backup where the server I'm using tends to get blocked in around the same timeframe. It's using openvpn/wireguard as the underlying protocol which doesn't try to obfuscate itself so I suspect traffic pattern analysis plays a larger role in what gets blocked than the protocol itself. The exception was my recent trip week-long trip where I was mostly cycling between two servers without noticing either being blocked.
- 1y ago

smoovb 1y ago

Interesting, a apparent GFW insider (GFW官方代表) making a statement on the leak and its source: https://github.com/net4people/bbs/issues/519#issuecomment-3300358468 https://github.com/net4people/bbs/issues/519#issuecomment-33...