7 ms·

There are "standard practices" when it comes to usage of the mount tool and TrueCrypt does not follow them and its inability to follow them is what leads to thi

There are "standard practices" when it comes to usage of the mount tool and TrueCrypt does not follow them and its inability to follow them is what leads to this privilege escalation. Another "standard practice" TrueCrypt is not following is its creation of the mount point with 0777 permissions at "/media",a directory that is world readable.A "standard practice" is to have mount points at "/run/media/$USER" or "/media/$USER" or anywhere else where only the owner of the mount point has access to it.This is another security issue that need to be addressed.

simoncion 12y ago
Everywhere I look to see how to use TrueCrypt on Linux, I see it being used as just another encrypted block device. This strongly indicates that any policy issues that you're bringing up aren't the fault of TrueCrypt, but rather are issues with whatever mount scripts you're using. Can you point me to some documentation that would give me cause to believe otherwise?
- mhogomchungu 12y ago
  What steps are involved when mounting a TrueCrypt volume? This is what happens when you mount a TrueCrypt volume using their GUI application in linux. 1. A TrueCrypt volume is unlocked by TrueCrypt. 2. The unlocked volume is mounted by TrueCrypt. The mounting "script" in this case is TrueCrypt and hence it is TrueCrypt's fault. If you unlock the volume using TrueCrypt and then mount the unlocked volume using udisks,then it would be udisks' fault. If you unlock the volume using TrueCrypt and then mount the volume yourself,then it will be your fault. The fault is in the person who is doing the mounting and in TrueCrypt's GUI application case,TrueCrypt is the one who is doing the mounting and hence its TrueCrypt's fault. How are you using TrueCrypt GUI if TrueCrypt is not the part that does the mounting? I am not aware of any documentations but i am aware of discussions around "best practices" when it comes to usage of the mount command.
  - simoncion 12y ago
    > How are you using TrueCrypt GUI if TrueCrypt is not the part that does the mounting? There's a GUI? Huh. Then, then answer to your question is "I'm not using the TrueCrypt GUI.". This documentation is pretty representative of what I've been seeing (and what has worked for me) when I've looked in to using TrueCrypt on Linux: http://www.gentoo-wiki.info/TrueCrypt http://www.gentoo-wiki.info/TrueCrypt > The mounting "script" in this case is TrueCrypt and hence it is TrueCrypt's fault. I was completely unaware of the existence of a TrueCrypt GUI. I understood TrueCrypt to be the block device encryption software that filled the same role as LUKS. So, you should refine your claim. Rather than saying "TrueCrypt mounts things insecurely." say "There are helper scripts distributed with TrueCrypt that mount things insecurely. They should be fixed.". > I am aware of discussions around "best practices" when it comes to usage of the mount command. The thing about Best Practices is that they don't work in all circumstances. If the volume mounting scripts packaged with TrueCrypt get updated, any defaults should be configurable, as there exist folks who need suid binaries in their TC volumes, as well as folks who don't like mounting things in /run . :)
    - mhogomchungu 12y ago
      It sounds like you are trying to deflect the fault away from TrueCrypt.I looked at the link you provided and i opened a TrueCrypt volume with this command: [root@mtz zc]# truecrypt ./rrr.img ../ink -p xxx [root@mtz zc]# So i opened it from the command line,i looked at the mounted volume and it was also mounted without "nosuid" option and hence the same problematic behavior is there even when TrueCrypt is used from the terminal. Even when using the CLI component,TrueCrypt automatically does the mounting and hence its TrueCrypt's fault. The mounting part is not done by a third party script that just happen to be bundled with TrueCrypt,it is done as a core part of TrueCrypt.The "mount" command is set here[1] and executed here[2]. You can walk up the code path to see where the "nosuid" options should have been set but isnt. Its kind of hard to follow discussions here so if you want to take this further then respond to my email address at mhogomchungu at Gmail Dot com [1] https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f519a31ef7de5bd7f0d0d318e8c/src/Core/Unix/CoreUnix.cpp#L376 https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f... [2] https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f519a31ef7de5bd7f0d0d318e8c/src/Platform/Unix/Process.cpp#L83 https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f... ps: ciphershed is a TrueCrypt fork.You can look up TrueCrypt's original source code if you dont trust the link i gave as i couldnt find easily taggable TrueCrypt source code online

simoncion 12y ago

Everywhere I look to see how to use TrueCrypt on Linux, I see it being used as just another encrypted block device. This strongly indicates that any policy issues that you're bringing up aren't the fault of TrueCrypt, but rather are issues with whatever mount scripts you're using. Can you point me to some documentation that would give me cause to believe otherwise?

mhogomchungu 12y ago
What steps are involved when mounting a TrueCrypt volume? This is what happens when you mount a TrueCrypt volume using their GUI application in linux. 1. A TrueCrypt volume is unlocked by TrueCrypt. 2. The unlocked volume is mounted by TrueCrypt. The mounting "script" in this case is TrueCrypt and hence it is TrueCrypt's fault. If you unlock the volume using TrueCrypt and then mount the unlocked volume using udisks,then it would be udisks' fault. If you unlock the volume using TrueCrypt and then mount the volume yourself,then it will be your fault. The fault is in the person who is doing the mounting and in TrueCrypt's GUI application case,TrueCrypt is the one who is doing the mounting and hence its TrueCrypt's fault. How are you using TrueCrypt GUI if TrueCrypt is not the part that does the mounting? I am not aware of any documentations but i am aware of discussions around "best practices" when it comes to usage of the mount command.
- simoncion 12y ago
  > How are you using TrueCrypt GUI if TrueCrypt is not the part that does the mounting? There's a GUI? Huh. Then, then answer to your question is "I'm not using the TrueCrypt GUI.". This documentation is pretty representative of what I've been seeing (and what has worked for me) when I've looked in to using TrueCrypt on Linux: http://www.gentoo-wiki.info/TrueCrypt http://www.gentoo-wiki.info/TrueCrypt > The mounting "script" in this case is TrueCrypt and hence it is TrueCrypt's fault. I was completely unaware of the existence of a TrueCrypt GUI. I understood TrueCrypt to be the block device encryption software that filled the same role as LUKS. So, you should refine your claim. Rather than saying "TrueCrypt mounts things insecurely." say "There are helper scripts distributed with TrueCrypt that mount things insecurely. They should be fixed.". > I am aware of discussions around "best practices" when it comes to usage of the mount command. The thing about Best Practices is that they don't work in all circumstances. If the volume mounting scripts packaged with TrueCrypt get updated, any defaults should be configurable, as there exist folks who need suid binaries in their TC volumes, as well as folks who don't like mounting things in /run . :)
  - mhogomchungu 12y ago
    It sounds like you are trying to deflect the fault away from TrueCrypt.I looked at the link you provided and i opened a TrueCrypt volume with this command: [root@mtz zc]# truecrypt ./rrr.img ../ink -p xxx [root@mtz zc]# So i opened it from the command line,i looked at the mounted volume and it was also mounted without "nosuid" option and hence the same problematic behavior is there even when TrueCrypt is used from the terminal. Even when using the CLI component,TrueCrypt automatically does the mounting and hence its TrueCrypt's fault. The mounting part is not done by a third party script that just happen to be bundled with TrueCrypt,it is done as a core part of TrueCrypt.The "mount" command is set here[1] and executed here[2]. You can walk up the code path to see where the "nosuid" options should have been set but isnt. Its kind of hard to follow discussions here so if you want to take this further then respond to my email address at mhogomchungu at Gmail Dot com [1] https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f519a31ef7de5bd7f0d0d318e8c/src/Core/Unix/CoreUnix.cpp#L376 https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f... [2] https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f519a31ef7de5bd7f0d0d318e8c/src/Platform/Unix/Process.cpp#L83 https://github.com/CipherShed/CipherShed/blob/e8529e95d89d3f... ps: ciphershed is a TrueCrypt fork.You can look up TrueCrypt's original source code if you dont trust the link i gave as i couldnt find easily taggable TrueCrypt source code online