#VU9328 Referrer policy bypass in Mozilla Firefox - CVE-2017-7842

Vulnerability identifier: #VU9328

Vulnerability risk: Low

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

CVE-ID: CVE-2017-7842

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

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

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to bypass certain security restrictions.

If a document’s Referrer Policy attribute is set to "no-referrer" sometimes two network requests are made for <link> elements instead of one. One of these requests includes the referrer instead of respecting the set policy to not include a referrer on requests.

Mitigation
Update to version Firefox 57.

Vulnerable software versions

Mozilla Firefox: 53.0 - 56.0.1

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2017-24/

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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.