Bug 445829 (CVE-2008-1803) - CVE-2008-1803 rdesktop: channel_process() Integer Signedness Vulnerability
Summary: CVE-2008-1803 rdesktop: channel_process() Integer Signedness Vulnerability
Status: CLOSED ERRATA
Alias: CVE-2008-1803
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL: http://nvd.nist.gov/nvd.cfm?cvename=C...
Whiteboard: source=internet,reported=20080507,pub...
Keywords: Security
Depends On: 445841 445842 445843 452978 452979
Blocks:
TreeView+ depends on / blocked
 
Reported: 2008-05-09 10:19 UTC by Tomas Hoger
Modified: 2008-07-25 06:23 UTC (History)
3 users (show)

(edit)
Clone Of:
(edit)
Last Closed: 2008-07-25 06:23:55 UTC


Attachments (Terms of Use)


External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2008:0575 normal SHIPPED_LIVE Moderate: rdesktop security update 2008-07-24 17:15:19 UTC

Description Tomas Hoger 2008-05-09 10:19:33 UTC
iDefense published advisory affecting rdesktop:

DESCRIPTION:
Remote exploitation of an integer signedness vulnerability in rdesktop, as
included in various vendors' operating system distributions, allows attackers
to execute arbitrary code with the privileges of the logged-in user.

The vulnerability exists within the code responsible for reallocating dynamic
buffers. The rdesktop xrealloc() function uses a signed comparison to determine
if the requested allocation size is less than 1. When this occurs, the function
will incorrectly set the allocation size to be 1. This results in an improperly
sized heap buffer being allocated, which can later be overflowed.

ANALYSIS:
Exploitation of this vulnerability results in the execution of arbitrary code
with the privileges of the logged in user. In order to exploit this
vulnerability, an attacker must persuade a targeted user to connect to a
malicious RDP server. 

Reference:
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=698

Upstream patch:
http://rdesktop.cvs.sourceforge.net/rdesktop/rdesktop/rdesktop.c?r1=1.161&r2=1.162

Comment 5 Tomas Hoger 2008-05-14 06:12:03 UTC
Upstream released version 1.6.0 which address this issue:

http://sourceforge.net/mailarchive/message.php?msg_name=20080511065217.GA24455%40cse.unsw.EDU.AU


Comment 6 Fedora Update System 2008-05-14 22:08:24 UTC
rdesktop-1.6.0-1.fc9 has been pushed to the Fedora 9 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2008-05-14 22:12:26 UTC
rdesktop-1.6.0-1.fc8 has been pushed to the Fedora 8 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 8 Fedora Update System 2008-05-14 22:15:08 UTC
rdesktop-1.6.0-1.fc7 has been pushed to the Fedora 7 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Tomas Hoger 2008-06-23 16:48:40 UTC
This issue did not affect rdesktop packages as shipped in Red Hat Enterprise
Linux 3 and 4.  xrealloc in those versions (1.2.0 and 1.3.1 respectively) does
not set size to 1 when size is lower than 1.  Negative size values are cast to
large positive when passed as size_t-typed argument to realloc.


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