Vulnerability identifier: #VU6324

Vulnerability risk: High

CVSSv3.1: 8.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-5440

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to use-after-free error during XSLT processing due to a failure to propagate error conditions during matching while evaluating context, leading to objects being used when they no longer exist. A remote attacker can trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation
Update to Firefox 53, Firefox ESR 45.9 or Firefox ESR 52.1.

Vulnerable software versions

Mozilla Firefox: 52 - 52.0.2

Firefox ESR: 52.0 - 52.0.2, 45 - 45.8

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2017-10/
http://www.mozilla.org/en-US/security/advisories/mfsa2017-11/
http://www.mozilla.org/en-US/security/advisories/mfsa2017-12/

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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?

No. We are not aware of malware exploiting this vulnerability.