CVE-2021-28834

Public Exploit

Description

Kramdown before 2.3.1 does not restrict Rouge formatters to the Rouge::Formatters namespace, and thus arbitrary classes can be instantiated.

9.8

CVSS

Severity: Critical

CVSS 3.1 •

CVSS 2.0 •

EPSS 1.38% Top 25%

Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory debian.org

Affected: n/a n/a

References

Link	Tags
https://github.com/gettalong/kramdown/pull/708	third party advisory exploit
https://gitlab.com/gitlab-org/gitlab/-/commit/179329b5c3c118924fb242dc449d06b4ed6ccb66	third party advisory patch
https://github.com/gettalong/kramdown/compare/REL_2_3_0...REL_2_3_1	third party advisory patch
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S3BBLUIDCUUR3NEE4NJLOCCAV3ALQ3O6/	vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SYOLQKFL6IJCQLBXV34Z4TI4O54GESPR/	vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NJCJVYHPY6LNUFM6LYZIAUIYOMVT5QGV/	vendor advisory
https://www.debian.org/security/2021/dsa-4890	third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-28834?: CVE-2021-28834 has been scored as a critical severity vulnerability.
How to fix CVE-2021-28834?: To fix CVE-2021-28834, 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-2021-28834 being actively exploited in the wild?: It is possible that CVE-2021-28834 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.

This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.