Bug 596574

Summary:	cve-2016-7942 and forwards: Multiple vulnerabilities in X11 protocol libraries
Product:	Gentoo Security	Reporter:	Ian Zimmerman <nobrowser>
Component:	Vulnerabilities	Assignee:	Gentoo Security <security>
Status:	RESOLVED DUPLICATE
Severity:	normal
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description Ian Zimmerman 2016-10-08 19:42:17 UTC

According to the post on oss-security [1], where pointers to upstream fixes can also be found:

Tobias Stoeckmann from the OpenBSD project has discovered a number of
issues in the way various X client libraries handle the responses they
receive from servers, and has worked with X.Org's security team to
analyze, confirm, and fix these issues. These issue come in addition
to the ones discovered by Ilja van Sprundel in 2013.

Most of these issues stem from the client libraries trusting the
server to send correct protocol data, and not verifying that the
values will not overflow or cause other damage. Most of the time X
clients & servers are run by the same user, with the server more
privileged than the clients, so this is not a problem, but there are
scenarios in which a privileged client can be connected to an
unprivileged server, for instance, connecting a setuid X client (such
as a screen lock program) to a virtual X server (such as Xvfb or
Xephyr) which the user has modified to return invalid data,
potentially allowing the user to escalate their privileges.

[1]
https://marc.info/?l=oss-security&m=147559434726758&w=2


Reproducible: Always

Comment 1 Mart Raudsepp gentoo-dev

2016-10-08 20:45:34 UTC


*** This bug has been marked as a duplicate of bug 596182 ***