Home page logo
/

oss-sec logo oss-sec mailing list archives

Re: Linux procfs infoleaks via self-read by a SUID/SGID program (was: CVE-2011-3637 Linux kernel: proc: fix Oops on invalid /proc/<pid>/maps access)
From: Solar Designer <solar () openwall com>
Date: Thu, 9 Feb 2012 10:55:23 +0400

On Thu, Feb 09, 2012 at 03:31:34AM +0100, Jason A. Donenfeld wrote:
On Wed, Feb 8, 2012 at 11:12, Solar Designer <solar () openwall com> wrote:
BTW, what version of chsh did you test this with and what behavior do
you observe?  I was not able to get anything useful in this way out of
Owl's chsh (once enabled for non-root) - it just asks for the password,
but somehow fails to read it if one is entered on the tty (perhaps
there's some inconsistency in use of the tty vs. fd 0).  I suppose I'd
need to get past successful authentication for chsh's input to be
treated as the new shell name, in which case it'd get printed out (such
as in an error message) or/and put in /etc/passwd.

zx2c4 () ZX2C4-Laptop ~/Projects/Ploits/Local/CVE-2012-0056 $ gcc maps.c
zx2c4 () ZX2C4-Laptop ~/Projects/Ploits/Local/CVE-2012-0056 $ ./a.out
Changing the login shell for zx2c4
Enter the new value, or press ENTER for the default
        Login Shell [/bin/bash]: chsh: Invalid entry:
00400000-00408000 r-xp 00000000 fd:00 1444794
  /usr/bin/chsh

Hmm.  It does not even ask you for the password.  Perhaps you have
CHFN_AUTH in /etc/login.defs set to "no" or not set at all?  (On Owl,
it's "yes".)

Alexander


  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]