USN-3239-1: GNU C Library vulnerabilities

Ubuntu Security Notice USN-3239-1

20th March, 2017

eglibc, glibc vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS
  • Ubuntu 12.04 LTS

Summary

Several security issues were fixed in the GNU C Library.

Software description

  • eglibc - GNU C Library
  • glibc - GNU C Library

Details

It was discovered that the GNU C Library incorrectly handled the
strxfrm() function. An attacker could use this issue to cause a denial
of service or possibly execute arbitrary code. This issue only affected
Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2015-8982)

It was discovered that an integer overflow existed in the
_IO_wstr_overflow() function of the GNU C Library. An attacker could
use this to cause a denial of service or possibly execute arbitrary
code. This issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04
LTS. (CVE-2015-8983)

It was discovered that the fnmatch() function in the GNU C Library
did not properly handle certain malformed patterns. An attacker could
use this to cause a denial of service. This issue only affected Ubuntu
12.04 LTS and Ubuntu 14.04 LTS. (CVE-2015-8984)

Alexander Cherepanov discovered a stack-based buffer overflow in the
glob implementation of the GNU C Library. An attacker could use this
to specially craft a directory layout and cause a denial of service.
(CVE-2016-1234)

Florian Weimer discovered a NULL pointer dereference in the DNS
resolver of the GNU C Library. An attacker could use this to cause
a denial of service. (CVE-2015-5180)

Michael Petlan discovered an unbounded stack allocation in the
getaddrinfo() function of the GNU C Library. An attacker could use
this to cause a denial of service. (CVE-2016-3706)

Aldy Hernandez discovered an unbounded stack allocation in the sunrpc
implementation in the GNU C Library. An attacker could use this to
cause a denial of service. (CVE-2016-4429)

Tim Ruehsen discovered that the getaddrinfo() implementation in the
GNU C Library did not properly track memory allocations. An attacker
could use this to cause a denial of service. This issue only affected
Ubuntu 16.04 LTS. (CVE-2016-5417)

Andreas Schwab discovered that the GNU C Library on ARM 32-bit
platforms did not properly set up execution contexts. An attacker
could use this to cause a denial of service. (CVE-2016-6323)

Update instructions

The problem can be corrected by updating your system to the following package version:

Ubuntu 16.04 LTS:
libc6 2.23-0ubuntu6
Ubuntu 14.04 LTS:
libc6 2.19-0ubuntu6.10
Ubuntu 12.04 LTS:
libc6 2.15-0ubuntu10.16

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to reboot your computer to make
all the necessary changes.

References

CVE-2015-5180, CVE-2015-8982, CVE-2015-8983, CVE-2015-8984, CVE-2016-1234, CVE-2016-3706, CVE-2016-4429, CVE-2016-5417, CVE-2016-6323