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Ubuntu Security Notice USN-3372-1
July 31, 2017

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

- Ubuntu 12.04 ESM

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 versions:

Ubuntu 12.04 ESM:
A  libnss3A A A A A A A A A A A A A A A A A A A A A A A A A 2:3.28.4-0ubuntu0.12.04.1

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:
A  https://www.ubuntu.com/usn/usn-3372-1
A  CVE-2016-2183, CVE-2017-5461, CVE-2017-7502