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Bug 166857 - CAN-2005-2495 multiple integer overflows
CAN-2005-2495 multiple integer overflows
Product: Red Hat Enterprise Linux 3
Classification: Red Hat
Component: XFree86 (Show other bugs)
All Linux
medium Severity high
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Assigned To: Søren Sandmann Pedersen
David Lawrence
: Security
Depends On:
  Show dependency treegraph
Reported: 2005-08-26 10:50 EDT by Josh Bressers
Modified: 2014-06-18 05:07 EDT (History)
4 users (show)

See Also:
Fixed In Version: RHSA-2005-501
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2005-09-15 04:47:49 EDT
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Regression: ---
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Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2005:501 qe-ready SHIPPED_LIVE Important: XFree86 security update 2005-09-15 00:00:00 EDT

  None (edit)
Description Josh Bressers 2005-08-26 10:50:56 EDT
+++ This bug was initially created as a clone of Bug #166856 +++


What is going on here is that an X client is trying to allocate a pixmap
of size 9GB. Because of
an integer overflow this is not caught and instead a pixmap of size 1GB
is allocated. When the
client then tries to access the pixmap we get a server crash.

This seems exploitable to me: a client could allocate a pixmap of size
4GB + 4byte, causing
the server to allocate just 4 bytes. Then the client could use
XDrawPoint() and XGetImage() to
read and write any location in the X server address space. It could
first use XGetImage to search
for the stack, then use XDrawPoint to rewrite it to return into another
pixmap the client allocated,
thus getting the X server to execute arbitrary code.

This issue was discovered by Luke Hutchison, with the security implications and
patch found by Soeren Sandmann.
Comment 1 Mark J. Cox 2005-09-13 05:51:20 EDT
Public, removing embargo
Comment 2 Red Hat Bugzilla 2005-09-15 04:47:49 EDT
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


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