USN-3372-1: NSS vulnerability

Ubuntu Security Notice USN-3372-1

31st July, 2017

nss vulnerability

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

  • Ubuntu 12.04 LTS

Summary

Several security issues were fixed in NSS.

Software description

  • nss - Network Security Service library

Details

It was discovered that NSS incorrectly handled certain empty SSLv2
messages. A remote attacker could possibly use this issue to cause NSS to
crash, resulting in a denial of service. (CVE-2017-7502)

Karthik Bhargavan and Gaetan Leurent discovered that the DES and Triple DES
ciphers were vulnerable to birthday attacks. A remote attacker could
possibly use this flaw to obtain clear text data from long encrypted
sessions. This update causes NSS to limit use of the same symmetric key.
(CVE-2016-2183)

It was discovered that NSS incorrectly handled Base64 decoding. A remote
attacker could use this flaw to cause NSS to crash, resulting in a denial
of service, or possibly execute arbitrary code. (CVE-2017-5461)

Update instructions

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

Ubuntu 12.04 LTS:
libnss3 2:3.28.4-0ubuntu0.12.04.1

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

This update uses a new upstream release, which includes additional bug
fixes. After a standard system update you need to restart any applications
that use NSS, such as Evolution and Chromium, to make all the necessary
changes.

References

CVE-2016-2183, CVE-2017-5461, CVE-2017-7502