USN-1732-2: OpenSSL regression

Ubuntu Security Notice USN-1732-2

28th February, 2013

openssl regression

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

  • Ubuntu 12.10
  • Ubuntu 12.04 LTS

Summary

USN-1732-1 introduced a regression in OpenSSL.

Software description

  • openssl - Secure Socket Layer (SSL) cryptographic library and tools

Details

USN-1732-1 fixed vulnerabilities in OpenSSL. The fix for CVE-2013-0169 and
CVE-2012-2686 introduced a regression causing decryption failures on
hardware supporting AES-NI. This update temporarily reverts the security
fix pending further investigation. We apologize for the inconvenience.

Original advisory details:

Adam Langley and Wolfgang Ettlingers discovered that OpenSSL incorrectly
handled certain crafted CBC data when used with AES-NI. A remote attacker
could use this issue to cause OpenSSL to crash, resulting in a denial of
service. This issue only affected Ubuntu 12.04 LTS and Ubuntu 12.10.
(CVE-2012-2686)

Nadhem Alfardan and Kenny Paterson discovered that the TLS protocol as used
in OpenSSL was vulnerable to a timing side-channel attack known as the
"Lucky Thirteen" issue. A remote attacker could use this issue to perform
plaintext-recovery attacks via analysis of timing data. (CVE-2013-0169)

Update instructions

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

Ubuntu 12.10:
libssl1.0.0 1.0.1c-3ubuntu2.2
openssl 1.0.1c-3ubuntu2.2
Ubuntu 12.04 LTS:
libssl1.0.0 1.0.1-4ubuntu5.7
openssl 1.0.1-4ubuntu5.7

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

LP: 1133333