Moderate: glibc security, bug fix, and enhancement update

Synopsis

Moderate: glibc security, bug fix, and enhancement update

Type/Severity

Security Advisory: Moderate

Topic

Updated glibc packages that fix three security issues, several bugs, and
add various enhancements are now available for Red Hat Enterprise Linux 6.

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.

Description

The glibc packages provide the standard C libraries (libc), POSIX thread
libraries (libpthread), standard math libraries (libm), and the Name Server
Caching Daemon (nscd) used by multiple programs on the system. Without
these libraries, the Linux system cannot function correctly.

Multiple integer overflow flaws, leading to heap-based buffer overflows,
were found in glibc's memory allocator functions (pvalloc, valloc, and
memalign). If an application used such a function, it could cause the
application to crash or, potentially, execute arbitrary code with the
privileges of the user running the application. (CVE-2013-4332)

A flaw was found in the regular expression matching routines that process
multibyte character input. If an application utilized the glibc regular
expression matching mechanism, an attacker could provide specially-crafted
input that, when processed, would cause the application to crash.
(CVE-2013-0242)

It was found that getaddrinfo() did not limit the amount of stack memory
used during name resolution. An attacker able to make an application
resolve an attacker-controlled hostname or IP address could possibly cause
the application to exhaust all stack memory and crash. (CVE-2013-1914)

Among other changes, this update includes an important fix for the following
bug:

• Due to a defect in the initial release of the getaddrinfo() system call in Red
  Hat enterprise Linux 6.0, AF_INET and AF_INET6 queries resolved from the
  /etc/hosts file returned queried names as canonical names. This incorrect
  behavior is, however, still considered to be the expected behavior. As a result
  of a recent change in getaddrinfo(), AF_INET6 queries started resolving the
  canonical names correctly. However, this behavior was unexpected by applications
  that relied on queries resolved from the /etc/hosts file, and these applications
  could thus fail to operate properly. This update applies a fix ensuring that
  AF_INET6 queries resolved from /etc/hosts always return the queried name as
  canonical. Note that DNS lookups are resolved properly and always return the
  correct canonical names. A proper fix to AF_INET6 queries resolution from
  /etc/hosts may be applied in future releases; for now, due to a lack of
  standard, Red Hat suggests the first entry in the /etc/hosts file, that applies
  for the IP address being resolved, to be considered the canonical entry.
  (BZ#1022022)
  

These updated glibc packages also include additional bug fixes and
various enhancements. Space precludes documenting all of these changes
in this advisory. Users are directed to the Red Hat Enterprise Linux 6.5
Technical Notes, linked to in the References, for information on the
most significant of these changes.

All glibc users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues and add these
enhancements.

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 Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• 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

Fixes

• BZ - 552960 - Possible deadlock in pthread_mutex_lock/pthread_cond_wait
• BZ - 848748 - Malformed xdr request causes reading uninitialize memory and can cause huge memory leaks
• BZ - 903754 - Rename glibc release engineering related directory from `fedora' to `releng'
• BZ - 905874 - CVE-2013-0242 glibc: Buffer overrun (DoS) in regexp matcher by processing multibyte characters
• BZ - 929388 - serious CPU time regressions in the glibc math library
• BZ - 947882 - CVE-2013-1914 glibc: Stack (frame) overflow in getaddrinfo() when processing entry mapping to long list of address structures
• BZ - 952422 - sysconf(_SC_NPROCESSORS_ONLN) performance problem
• BZ - 966775 - [RHEL 6.4] BUG glibc causing double-whetstone performance degradation when compared to RHEL 6.3.
• BZ - 1007545 - CVE-2013-4332 glibc: three integer overflows in memory allocator

CVEs

• CVE-2013-0242
• CVE-2013-1914
• CVE-2013-4332

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.5_Technical_Notes/glibc.html#RHSA-2013-1605