Ubuntu 12.04 LTS / 14.04 LTS / 14.10 / 15.04 : nss vulnerabilities (USN-2672-1)

Medium Nessus Plugin ID 84666


The remote Ubuntu host is missing a security-related patch.


Karthikeyan Bhargavan discovered that NSS incorrectly handled state transitions for the TLS state machine. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to skip the ServerKeyExchange message and remove the forward-secrecy property. (CVE-2015-2721)

Watson Ladd discovered that NSS incorrectly handled Elliptical Curve Cryptography (ECC) multiplication. A remote attacker could possibly use this issue to spoof ECDSA signatures. (CVE-2015-2730)

As a security improvement, this update modifies NSS behaviour to reject DH key sizes below 768 bits, preventing a possible downgrade attack.

This update also refreshes the NSS package to version 3.19.2 which includes the latest CA certificate bundle.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.


Update the affected libnss3 package.

Plugin Details

Severity: Medium

ID: 84666

File Name: ubuntu_USN-2672-1.nasl

Version: $Revision: 1.6 $

Type: local

Agent: unix

Published: 2015/07/13

Modified: 2016/05/24

Dependencies: 12634

Risk Information

Risk Factor: Medium


Base Score: 4.3

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N

Temporal Vector: CVSS2#E:ND/RL:OF/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:libnss3, cpe:/o:canonical:ubuntu_linux:12.04:-:lts, cpe:/o:canonical:ubuntu_linux:14.04, cpe:/o:canonical:ubuntu_linux:14.10, cpe:/o:canonical:ubuntu_linux:15.04

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2015/07/09

Reference Information

CVE: CVE-2015-2721, CVE-2015-2730

BID: 75541

OSVDB: 124092, 124105

USN: 2672-1