RHSA-2014:0415 - Security Advisory

Topic

Updated libyaml packages that fix two security issues are now available for
Red Hat Common for Red Hat Enterprise Linux 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

YAML is a data serialization format designed for human readability and
interaction with scripting languages. LibYAML is a YAML parser and emitter
written in C.

A buffer overflow flaw was found in the way the libyaml library parsed URLs
in YAML documents. An attacker able to load specially crafted YAML input to
an application using libyaml could cause the application to crash or,
potentially, execute arbitrary code with the privileges of the user running
the application. (CVE-2014-2525)

An integer overflow flaw was found in the way the libyaml library handled
excessively long YAML tags. An attacker able to load specially crafted YAML
input to application using libyaml could cause the application to crash or,
potentially, execute arbitrary code with the privileges of the user running
the application. (CVE-2013-6393)

Red Hat would like to thank oCERT for reporting the CVE-2014-2525 issue.
oCERT acknowledges Ivan Fratric of the Google Security Team as the original
reporter. The CVE-2013-6393 issue was discovered by Florian Weimer of the
Red Hat Product Security Team.

Note: In their default configuration, applications distributed via the Red
Hat Common channel do not use the libyaml library for parsing YAML, and are
therefore not vulnerable to these issues.

All libyaml users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. All running
applications linked against the libyaml library must be restarted for this
update to take effect.

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
https://access.redhat.com/site/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386

Fixes

• BZ - 1033990 - CVE-2013-6393 libyaml: heap-based buffer overflow when parsing YAML tags
• BZ - 1078083 - CVE-2014-2525 libyaml: heap-based buffer overflow when parsing URLs

CVEs

• CVE-2013-6393
• CVE-2014-2525

References

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