CVE-2021-28834
medium
CVSS v3
—
CVSS v4 NEW
—
VIR risk
5.5
Description
Kramdown before 2.3.1 does not restrict Rouge formatters to the Rouge::Formatters namespace, and thus arbitrary classes can be instantiated.
Predictions
Exploit likelihood
30%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| arch | fixed | 2.3.1-1 | |
| sles | affected | | |
| debian | bookworm | fixed | 2.3.0-5 |
| debian | bullseye | fixed | 2.3.0-5 |
| debian | forky | fixed | 2.3.0-5 |
| debian | sid | fixed | 2.3.0-5 |
| debian | trixie | fixed | 2.3.0-5 |
References
- https://github.com/advisories/GHSA-52p9-v744-mwjj
- https://www.suse.com/security/cve/CVE-2021-28834.html
- https://nvd.nist.gov/vuln/detail/CVE-2021-28834
- https://github.com/gettalong/kramdown/pull/708
- https://github.com/stanhu/kramdown/commit/d6a1cbcb2caa2f8a70927f176070d126b2422760
- https://github.com/stanhu/kramdown/commit/ff0218aefcf00cd5a389e17e075d36cd46d011e2
- https://about.gitlab.com/releases/2021/03/17/security-release-gitlab-13-9-4-released/#remote-code-execution-via-unsafe-user-controlled-markdown-rendering-options
- https://github.com/gettalong/kramdown/compare/REL_2_3_0...REL_2_3_1
- https://gitlab.com/gitlab-org/gitlab/-/commit/179329b5c3c118924fb242dc449d06b4ed6ccb66
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NJCJVYHPY6LNUFM6LYZIAUIYOMVT5QGV
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/S3BBLUIDCUUR3NEE4NJLOCCAV3ALQ3O6
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SYOLQKFL6IJCQLBXV34Z4TI4O54GESPR
- https://www.debian.org/security/2021/dsa-4890
- https://security-tracker.debian.org/tracker/CVE-2021-28834
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.