CVE-2021-27291

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.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 2.52% Top 20%
Vendor Advisory debian.org Vendor Advisory debian.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5ce third party advisory exploit
https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14 third party advisory patch
https://lists.debian.org/debian-lts-announce/2021/03/msg00024.html third party advisory mailing list
https://www.debian.org/security/2021/dsa-4878 third party advisory vendor advisory
https://www.debian.org/security/2021/dsa-4889 third party advisory vendor advisory
https://lists.debian.org/debian-lts-announce/2021/05/msg00003.html third party advisory mailing list
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GSJRFHALQ7E3UV4FFMFU2YQ6LUDHAI55/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WSLD67LFGXOX2K5YNESSWAS4AGZIJTUQ/ vendor advisory
https://lists.debian.org/debian-lts-announce/2021/05/msg00006.html third party advisory mailing list

Frequently Asked Questions

What is the severity of CVE-2021-27291?
CVE-2021-27291 has been scored as a high severity vulnerability.
How to fix CVE-2021-27291?
To fix CVE-2021-27291, 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-2021-27291 being actively exploited in the wild?
It is possible that CVE-2021-27291 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~3% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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