Several security issues were fixed in NSS.
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)
27 April 2017
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in NSS.
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)
This update refreshes the NSS package to version 3.28.4 which includes the latest CA certificate bundle.
The problem can be corrected by updating your system to the following package versions:
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.