CVE-2021-27291

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.

Summary:

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.

Reference Links(if available):

  • 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://www.debian.org/security/2021/dsa-4878
  • https://www.debian.org/security/2021/dsa-4889
  • CVSS Score (if available)

    v2: / MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P

    v3: / HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

    Links to Exploits(if available)