CVE-2021-39186

Public Exploit
Improper Input Validation in GlobalNewFiles

Description

GlobalNewFiles is a MediaWiki extension maintained by Miraheze. Prior to commit number cee254e1b158cdb0ddbea716b1d3edc31fa4fb5d, the username column of the GlobalNewFiles special page is vulnerable to a stored XSS. Commit number cee254e1b158cdb0ddbea716b1d3edc31fa4fb5d contains a patch. As a workaround, one may disallow <,> (or other characters required to insert html/js) from being used in account names so an XSS is not possible.

Category

4.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.30%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory miraheze.org
Affected: miraheze GlobalNewFiles
Published at:
Updated at:

References

Link Tags
https://github.com/miraheze/GlobalNewFiles/security/advisories/GHSA-57p5-hqjq-h7vg third party advisory
https://github.com/miraheze/GlobalNewFiles/commit/cee254e1b158cdb0ddbea716b1d3edc31fa4fb5d third party advisory patch
https://phabricator.miraheze.org/T7935 third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2021-39186?
CVE-2021-39186 has been scored as a medium severity vulnerability.
How to fix CVE-2021-39186?
To fix CVE-2021-39186, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-39186 being actively exploited in the wild?
It is possible that CVE-2021-39186 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-39186?
CVE-2021-39186 affects miraheze GlobalNewFiles.
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