RHSA-2015:0016 - Security Advisory

Topic

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

Red Hat Product Security 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.

An out-of-bounds read flaw was found in the way glibc's iconv() function
converted certain encoded data to UTF-8. An attacker able to make an
application call the iconv() function with a specially crafted argument
could use this flaw to crash that application. (CVE-2014-6040)

It was found that the wordexp() function would perform command substitution
even when the WRDE_NOCMD flag was specified. An attacker able to provide
specially crafted input to an application using the wordexp() function, and
not sanitizing the input correctly, could potentially use this flaw to
execute arbitrary commands with the credentials of the user running that
application. (CVE-2014-7817)

The CVE-2014-7817 issue was discovered by Tim Waugh of the Red Hat
Developer Experience Team.

This update also fixes the following bugs:

• Previously, when an address lookup using the getaddrinfo() function for

the AF_UNSPEC value was performed on a defective DNS server, the server in
some cases responded with a valid response for the A record, but a referral
response for the AAAA record, which resulted in a lookup failure. A prior
update was implemented for getaddrinfo() to return the valid response, but
it contained a typographical error, due to which the lookup could under
some circumstances still fail. This error has been corrected and
getaddrinfo() now returns a valid response in the described circumstances.
(BZ#1172023)

• An error in the dlopen() library function previously caused recursive

calls to dlopen() to terminate unexpectedly or to abort with a library
assertion. This error has been fixed and recursive calls to dlopen() no
longer crash or abort. (BZ#1173469)

All glibc users are advised to 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
https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 i386
• Red Hat Enterprise Linux Server - AUS 6.6 x86_64
• 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 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 IBM z Systems - Extended Update Support 6.6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.6 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
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 6.6 x86_64
• Red Hat Enterprise Linux Server - TUS 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 1135841 - CVE-2014-6040 glibc: crash in code page decoding functions (IBM933, IBM935, IBM937, IBM939, IBM1364)
• BZ - 1157689 - CVE-2014-7817 glibc: command execution in wordexp() with WRDE_NOCMD specified

CVEs

• CVE-2014-7817
• CVE-2014-6040

References

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