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
Upstream released version 1.6.0 which address this issue: http://sourceforge.net/mailarchive/message.php?msg_name=20080511065217.GA24455%40cse.unsw.EDU.AU
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.
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.
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.
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.
This issue was addressed in: Red Hat Enterprise Linux: http://rhn.redhat.com/errata/RHSA-2008-0575.html Fedora: https://admin.fedoraproject.org/updates/F8/FEDORA-2008-3917 https://admin.fedoraproject.org/updates/F9/FEDORA-2008-3886