oss-sec mailing list archives
cve id request: insecure xauth cookie handling in fglrx (ati catalyst) driver
From: Michael Gilbert <michael.s.gilbert () gmail com>
Date: Mon, 18 Jul 2011 21:13:19 -0400
Hi, This may be an odd request. The proprietary fglrx driver has an info disclosure flaw in one of it's shell scripts [0]. It passes the xauth secret cookie in an insecure manner (such that it's exposed to prying eyes in the output of ps for example). The oddness in this request is that the driver is proprietary; but then again it is also included in most linux distributions in one form or another, so I think oss-sec is an appropriate forum. There is also a specific additional right granted in the script's header: "Distro maintainers may modify this reference script as necessary to conform to their distribution policies." This is debian bug #625868 [1], and I've commited an untested fix (I don't use authatieventsd myself) to our svn repo [2]. Note that there is discussion in the bug report claiming the debian-specific patch is to blame, but that conclusion is incorrect. The same flaw is also present in the upstream ati code as well. The debian code is only different in that it was made to handle a slightly different use case, but the underlying flaw is indeed present in both, so other distros are very likely affected as well. Note also that xauth's design makes this insecure usage seem like an obvious solution for the cookie handling problem, so there are probably many other flawed implementations like this, which could be found by grepping for xauth and auditing those cases handling the secret cookie. This may be something worth calling out as a CWE. Credit goes to Vincent Zweije who submitted the debian bug report. Best wishes, Mike [0] common/etc/ati/authatieventsd.sh [1] http://bugs.debian.org/625868 [2] svn://svn.debian.org/svn/pkg-fglrx/fglrx-driver/trunk
Current thread:
- cve id request: insecure xauth cookie handling in fglrx (ati catalyst) driver Michael Gilbert (Jul 18)
- Re: cve id request: insecure xauth cookie handling in fglrx (ati catalyst) driver Mike O'Connor (Jul 21)
- Re: cve id request: insecure xauth cookie handling in fglrx (ati catalyst) driver Michael Gilbert (Jul 22)
- Re: cve id request: insecure xauth cookie handling in fglrx (ati catalyst) driver Michael Gilbert (Aug 03)
- Re: cve id request: insecure xauth cookie handling in fglrx (ati catalyst) driver Mike O'Connor (Jul 21)