Opened 9 years ago

Closed 9 years ago

#6135 closed defect (fixed)

xorg-server-1.17.1

Reported by: ken@… Owned by: Fernando de Oliveira
Priority: normal Milestone: 7.7
Component: BOOK Version: SVN
Severity: normal Keywords:
Cc:

Description

from the announcement:

Fixes for CVE 2015-0255. ...

Keith Packard (1):
      Release 1.17.1

Olivier Fourdan (2):
      xkb: Don't swap XkbSetGeometry data in the input buffer
      xkb: Check strings length against request size

And from Peter Hutterer's Security Advisory -

X.Org Security Advisory: Feb 10, 2015 - CVE-2015-0255
Information leak in the XkbSetGeometry request of X servers
===========================================================
Description:
============
Olivier Fourdan from Red Hat has discovered a protocol handling issue in the
way the X server code base handles the XkbSetGeometry request.

The issue stems from the server trusting the client to send valid string
lengths in the request data. A malicious client with string lengths exceeding
the request length can cause the server to copy adjacent memory data into the
XKB structs. This data is then available to the client via the XkbGetGeometry
request.
The data length is at least up to 64k, it is possible to obtain more data by
chaining strings, each string length is then determined by whatever happens to
be in that 16-bit region of memory.

A similarly crafted request can likely cause the X server to crash.

This issue has been assigned CVE-2015-0255

Affected Versions:
==================
This bug appears to have been introduced in X11R6.1 (March 1996) and is thus
believed to be present in every X server release since, including the current
stable releases 1.16.3 and 1.17.0

Fixes:
======
A fix is available via the patch linked below which is intended to be included
in xorg-server-1.16.4 and 1.17.1
http://cgit.freedesktop.org/xorg/xserver/commit/?id=20079c36cf7d377938ca5478447d8b9045cb7d43

Note that this patch requires another patch to apply without conflicts:
http://cgit.freedesktop.org/xorg/xserver/commit/?id=81c90dc8f0aae3b65730409b1b615b5fa7280ebd

Thanks:
=======
The X.Org Foundation thanks Olivier for bringing this issue to our attention
and providing the fixes.

I'm only raising this, anyone who wishes can take it.

Change History (2)

comment:1 by Fernando de Oliveira, 9 years ago

Owner: changed from blfs-book@… to Fernando de Oliveira
Status: newassigned

comment:2 by Fernando de Oliveira, 9 years ago

Resolution: fixed
Status: assignedclosed

Fixed at 15490.

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