USN-3239-2: GNU C Library Regression

21 March 2017

eglibc, glibc regression

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

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

Summary

USN-3239-1 introduced a regression in the GNU C Library.

Software Description

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

Details

USN-3239-1 fixed vulnerabilities in the GNU C Library. Unfortunately, the fix for CVE-2015-5180 introduced an internal ABI change within the resolver library. This update reverts the change. We apologize for the inconvenience.

Please note that long-running services that were restarted to compensate for the USN-3239-1 update may need to be restarted again.

Original advisory 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 versions:

Ubuntu 16.04 LTS
libc6 - 2.23-0ubuntu7
Ubuntu 14.04 LTS
libc6 - 2.19-0ubuntu6.11
Ubuntu 12.04 LTS
libc6 - 2.15-0ubuntu10.17

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