RHSA-2010:0894 - Security Advisory

Topic

Updated systemtap packages that fix two security issues are now available
for Red Hat Enterprise Linux 5 and 6.

The Red Hat Security Response Team has rated this update as having
important 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.

Description

SystemTap is an instrumentation system for systems running the Linux
kernel, version 2.6. Developers can write scripts to collect data on the
operation of the system. staprun, the SystemTap runtime tool, is used for
managing SystemTap kernel modules (for example, loading them).

It was discovered that staprun did not properly sanitize the environment
before executing the modprobe command to load an additional kernel module.
A local, unprivileged user could use this flaw to escalate their
privileges. (CVE-2010-4170)

It was discovered that staprun did not check if the module to be unloaded
was previously loaded by SystemTap. A local, unprivileged user could use
this flaw to unload an arbitrary kernel module that was not in use.
(CVE-2010-4171)

Note: After installing this update, users already in the stapdev group must
be added to the stapusr group in order to be able to run the staprun tool.

Red Hat would like to thank Tavis Ormandy for reporting these issues.

SystemTap users should upgrade to these updated packages, which contain
backported patches to correct these issues.

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

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 653604 - CVE-2010-4170 Systemtap: Insecure loading of modules
• BZ - 653606 - CVE-2010-4171 Systemtap: Ability to remove unused modules by unprivileged user

CVEs

• CVE-2010-4170
• CVE-2010-4171

References

• https://access.redhat.com/security/updates/classification/#important