VulnerabilityModified
CVE-2021-27291
Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS.
HIGH 7.5EPSS 3.91%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.91%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 3.91% probability · 90th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-1333
- Affected
- pygments/pygments · debian/debian linux · fedoraproject/fedora
- Source
- cve@mitre.org
References
- https://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5ceExploit, Third Party Advisory
- https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14Patch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00024.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00003.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00006.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GSJRFHALQ7E3UV4FFMFU2YQ6LUDHAI55/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WSLD67LFGXOX2K5YNESSWAS4AGZIJTUQ/
- https://www.debian.org/security/2021/dsa-4878Third Party Advisory
- https://www.debian.org/security/2021/dsa-4889Third Party Advisory
- https://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5ceExploit, Third Party Advisory
- https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14Patch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00024.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00003.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/05/msg00006.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GSJRFHALQ7E3UV4FFMFU2YQ6LUDHAI55/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WSLD67LFGXOX2K5YNESSWAS4AGZIJTUQ/
- https://www.debian.org/security/2021/dsa-4878Third Party Advisory
- https://www.debian.org/security/2021/dsa-4889Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.