#VU34951 Cross-site scripting in MediaWiki - CVE-2019-19910

Vulnerability identifier: #VU34951

Vulnerability risk: Low

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

CVE-ID: CVE-2019-19910

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
MediaWiki
Web applications / CMS

Vendor: MediaWiki.org

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

The MinervaNeue Skin in MediaWiki from 2019-11-05 to 2019-12-13 (1.35 and/or 1.34) mishandles certain HTML attributes, as demonstrated by IMG onmouseover= (impact is XSS) and IMG src=http (impact is disclosing the client's IP address). This can occur within a talk page topical header that is viewed within a mobile (MobileFrontend) context.

Mitigation
Install update from vendor's website.

Vulnerable software versions

MediaWiki: 1.34 - 1.35

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External links
https://gerrit.wikimedia.org/r/q/Ida471291f1698387a26736931ab17e6899e05b51
https://phabricator.wikimedia.org/T240487

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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.