Ubuntu update for Firefox

1) Security bypass

EUVDB-ID: #VU1831

Risk: Critical

CVSSv3.1: 9.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2015-4495

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerabiity allows a remote attacker to bypass security restrictions on the target system.

The weakness exists due to improper input validation. A remote attacker can create a specially crafted PDF file, trick the victim into opening it, bypass same-origin policy and inject arbitrary JavaScript into the built-in PDF Viewer to gain access to arbitrary files on the system.

Successful exploitation of this vulnerability may result in access to local files and privilege escalation, leading to system compromise.

Note: the vulnerability was being actively exploited.

Mitigation

Update the affected packages

Ubuntu 15.04:

firefox 39.0.3+build2-0ubuntu0.15.04.1

Ubuntu 14.04 LTS:

firefox 39.0.3+build2-0ubuntu0.14.04.1

Ubuntu 12.04 LTS:

firefox 39.0.3+build2-0ubuntu0.12.04.1

Vulnerable software versions

Ubuntu: 12.04 - 14.04

External links

http://www.ubuntu.com/usn/usn-2707-1/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.