USN-1732-2: OpenSSL regression

Releases

• Ubuntu 12.10
• Ubuntu 12.04

Packages

• 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 versions:

Ubuntu 12.10

• libssl1.0.0 - 1.0.1c-3ubuntu2.2
• openssl - 1.0.1c-3ubuntu2.2

Ubuntu 12.04

• libssl1.0.0 - 1.0.1-4ubuntu5.7
• openssl - 1.0.1-4ubuntu5.7

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

References

• https://launchpad.net/bugs/1133333