Vulnerability identifier: #VU6330

Vulnerability risk: High

CVSSv3.1: 8.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2017-5447

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: Yes

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 boundary error when processing glyph widths during text layout. A remote attacker can trigger out-of-bounds read and gain access to sensitive system memory.

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. However, proof of concept for this vulnerability is available.