CVE-2021-27291
Published: March 17, 2021Last modified: November 8, 2023
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.5 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | py3-pygments | Not affected (2.13.0-r1) |
| Stream | py3-pygments | Not affected (2.16.1-r0) |
References
- https://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5ce
- https://github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14
- https://lists.debian.org/debian-lts-announce/2021/03/msg00024.html
- https://lists.debian.org/debian-lts-announce/2021/05/msg00003.html
- https://lists.debian.org/debian-lts-announce/2021/05/msg00006.html
- 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-4878
- https://www.debian.org/security/2021/dsa-4889