8.5 - RHSA-2010:0458

Problem Description:

Updated perl packages that fix multiple security issues are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64 Red Hat Enterprise Linux Desktop (v. 5 client) - i386, x86_64

3. Description:

Perl is a high-level programming language commonly used for system administration utilities and web programming. The Safe extension module allows users to compile and execute Perl code in restricted compartments. The File::Path module allows users to create and remove directory trees.

The Safe module did not properly restrict the code of implicitly called methods (such as DESTROY and AUTOLOAD) on implicitly blessed objects returned as a result of unsafe code evaluation. These methods could have been executed unrestricted by Safe when such objects were accessed or destroyed. A specially-crafted Perl script executed inside of a Safe compartment could use this flaw to bypass intended Safe module restrictions. (CVE-2010-1168)

The Safe module did not properly restrict code compiled in a Safe compartment and executed out of the compartment via a subroutine reference returned as a result of unsafe code evaluation. A specially-crafted Perl script executed inside of a Safe compartment could use this flaw to bypass intended Safe module restrictions, if the returned subroutine reference was called from outside of the compartment. (CVE-2010-1447)

Multiple race conditions were found in the way the File::Path module's rmtree function removed directory trees. A malicious, local user with write access to a directory being removed by a victim, running a Perl script using rmtree, could cause the permissions of arbitrary files to be changed to world-writable and setuid, or delete arbitrary files via a symbolic link attack, if the victim had the privileges to change the permissions of the target files or to remove them. (CVE-2008-5302, CVE-2008-5303)

Red Hat would like to thank Tim Bunce for responsibly reporting the CVE-2010-1168 and CVE-2010-1447 issues. Upstream acknowledges Nick Cleaton as the original reporter of CVE-2010-1168, and Tim Bunce and Rafaël Garcia-Suarez as the original reporters of CVE-2010-1447.

These packages upgrade the Safe extension module to version 2.27. Refer to the Safe module's Changes file, linked to in the References, for a full list of changes.

Users of perl are advised to upgrade to these updated packages, which correct these issues. All applications using the Safe or File::Path modules must be restarted for this update to take effect.

4. Solution:

Before applying this update, make sure all previously-released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at http://kbase.redhat.com/faq/docs/DOC-11259

5. Bugs fixed (http://bugzilla.redhat.com/):

473450 - CVE-2008-5302 perl: File::Path rmtree race condition (CVE-2005-0448) reintroduced after upstream rebase to 5.8.8-1 474217 - CVE-2008-5303 symlink perl: File::Path rmtree race condition (CVE-2004-0452) reintroduced after upstream rebase to 5.8.8-1 576508 - CVE-2010-1168 perl Safe: Intended restriction bypass via object references 588269 - CVE-2010-1447 perl: Safe restriction bypass when reference to subroutine in compartment is called from outside