[Secure-testing-team] Bug#612032: vulnerability: rewrite arbitrary user file

[Kees Cook]

Package: tesseract
Version: 2.04-2
Severity: grave
Tags: security
Justification: user security hole
User: ubuntu-devel at lists.ubuntu.com
Usertags: origin-ubuntu natty

This bug report was also filed in Ubuntu and can be found at
http://launchpad.net/bugs/607297
The description, from segooon, follows:

Hi, I've just discovered that tesseract-ocr is vulnerable to rewriting any user file:

DEBUG_WIN::DEBUG_WIN(                    //constructor
....
  length +=
    sprintf (command + length,
    "\"stty opost; tty >/tmp/debug%d; while [ -s /tmp/debug%d ]\ndo\nsleep 1\ndone\" &\n",
    pid, pid);

Here attacker can create link to any file in the system that user may write to. The only he has to know - the pid of process. As it is (last PID + 1) by default, it is not difficult to guess.

Thanks.

-- System Information:
Debian Release: squeeze/sid
  APT prefers natty
  APT policy: (500, 'natty')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.37-12-generic (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash