Vulnerability identifier: #VU8629

Vulnerability risk: Low

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-7823

CWE-ID: CWE-79

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 perform XSS attacks.

The content security policy (CSP) sandbox directive did not create a unique origin for the document, causing it to behave as if the allow-same-origin keyword were always specified. This could allow a Cross-Site Scripting (XSS) attack to be launched from unsafe content.

Mitigation
Update to version 56.0.

Vulnerable software versions

Mozilla Firefox: 48.0 - 55.0.3

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2017-21/

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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.