#VU6334 Sendbox bypass in Mozilla Firefox and Firefox ESR - CVE-2017-5455

Vulnerability identifier: #VU6334

Vulnerability risk: High

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2017-5455

CWE-ID: CWE-265

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 escape sendbox.

The vulnerability exists due to an error in internal feed reader APIs implementation. A remote attacker can use escape the sendbox and leverage another remote code execution vulnerability to compromise vulnerable system.

Successful exploitation of the vulnerability may allow an attacker to escape sendbox and potentially compromise vulnerable system.

Mitigation
Update to Firefox 53 or Firefox ESR 52.1.

Vulnerable software versions

Mozilla Firefox: 52 - 52.0.2

Firefox ESR: 52.0 - 52.0.2

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2017-10/
https://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.