CVE-2021-27291: High severity Pygments Pygments vulnerability

Published Jan 11, 2021
·
Updated

A denial of service attack was discovered against pygments. Some of the regular expressions used to tokenise source code for highlighting have exponential complexity. A specially crafted input file could cause pygments to take effectively infinite time to parse, consuming CPU resources and denying access to the service.

Other sources

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.

— Microsoft

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.

Affected Software

43 affected componentsFixes available
debian/pygments<=2.3.1+dfsg-1+deb10u1, <=2.7.1+dfsg-2, <=2.3.1+dfsg-1
2.3.1+dfsg-1+deb10u22.7.1+dfsg-2.1
redhat/automation-hub<0:4.2.2-1.el7
0:4.2.2-1.el7
redhat/python3-django<0:2.2.18-1.el7
0:2.2.18-1.el7
redhat/python-bleach<0:3.3.0-1.el7
0:3.3.0-1.el7
redhat/python-bleach-allowlist<0:1.0.3-1.el7
0:1.0.3-1.el7
redhat/python-galaxy-importer<0:0.2.15-1.el7
0:0.2.15-1.el7
redhat/python-galaxy-ng<0:4.2.2-1.el7
0:4.2.2-1.el7
redhat/python-pulp-ansible<1:0.5.6-1.el7
1:0.5.6-1.el7
redhat/automation-hub<0:4.2.2-1.el8
0:4.2.2-1.el8
redhat/python3-django<0:2.2.18-1.el8
0:2.2.18-1.el8
redhat/python-bleach<0:3.3.0-1.el8
0:3.3.0-1.el8
redhat/python-bleach-allowlist<0:1.0.3-1.el8
0:1.0.3-1.el8
redhat/python-galaxy-importer<0:0.2.15-1.el8
0:0.2.15-1.el8
redhat/python-galaxy-ng<0:4.2.2-1.el8
0:4.2.2-1.el8
redhat/python-pulp-ansible<1:0.5.6-1.el8
1:0.5.6-1.el8
redhat/resource-agents<0:4.1.1-98.el8
0:4.1.1-98.el8
redhat/python27-babel<0:0.9.6-10.el7
0:0.9.6-10.el7
redhat/python27-python<0:2.7.18-3.el7
0:2.7.18-3.el7
redhat/python27-python-jinja2<0:2.6-16.el7
0:2.6-16.el7
redhat/python27-python-pygments<0:1.5-5.el7
0:1.5-5.el7
debian/mediawiki
1:1.31.16-1+deb10u21:1.31.16-1+deb10u61:1.35.11-1~deb11u11:1.35.13-1~deb11u11:1.39.4-1~deb12u11:1.39.5-1~deb12u11:1.39.5-1
debian/pygments
2.3.1+dfsg-1+deb10u22.7.1+dfsg-2.12.14.0+dfsg-12.15.1+dfsg-1
ubuntu/pygments<2.7.1+dfsg-2ubuntu1
2.7.1+dfsg-2ubuntu1
ubuntu/pygments<2.2.0+dfsg-1ubuntu0.2
2.2.0+dfsg-1ubuntu0.2
ubuntu/pygments<2.3.1+dfsg-1ubuntu2.2
2.3.1+dfsg-1ubuntu2.2
ubuntu/pygments<2.3.1+dfsg-4ubuntu0.2
2.3.1+dfsg-4ubuntu0.2
ubuntu/pygments<2.7.1+dfsg-2ubuntu1
2.7.1+dfsg-2ubuntu1
ubuntu/pygments<2.7.4
2.7.4
ubuntu/pygments<2.1+dfsg-1ubuntu0.2
2.1+dfsg-1ubuntu0.2
ubuntu/pygments<1.6+dfsg-1ubuntu1.1+
1.6+dfsg-1ubuntu1.1+
ubuntu/pygments<2.7.1+dfsg-2ubuntu1
2.7.1+dfsg-2ubuntu1
ubuntu/pygments<2.7.1+dfsg-2ubuntu1
2.7.1+dfsg-2ubuntu1
ubuntu/pygments<2.7.1+dfsg-2ubuntu1
2.7.1+dfsg-2ubuntu1
ubuntu/pygments<2.7.1+dfsg-2ubuntu1
2.7.1+dfsg-2ubuntu1
redhat/python-pygments<2.7.4
2.7.4
pip/pygments>=1.1<2.7.4
2.7.4
Pygments Pygments>=1.1<2.7.4
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Fedoraproject Fedora=32
Fedoraproject Fedora=33
Microsoft azl3 python-pygments 2.7.4-1
Patch available
Microsoft azl3 python-pygments 2.5.2-1
Patch available

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/pygments to a version that resolves this vulnerability.

    Fixed in 2.3.1+dfsg-1+deb10u2Fixed in 2.7.1+dfsg-2.1
  2. Upgrade

    Upgrade redhat/automation-hub to a version that resolves this vulnerability.

    Fixed in 0:4.2.2-1.el7
  3. Upgrade

    Upgrade redhat/python3-django to a version that resolves this vulnerability.

    Fixed in 0:2.2.18-1.el7
  4. Upgrade

    Upgrade redhat/python-bleach to a version that resolves this vulnerability.

    Fixed in 0:3.3.0-1.el7
  5. Upgrade

    Upgrade redhat/python-bleach-allowlist to a version that resolves this vulnerability.

    Fixed in 0:1.0.3-1.el7
  6. Upgrade

    Upgrade redhat/python-galaxy-importer to a version that resolves this vulnerability.

    Fixed in 0:0.2.15-1.el7
  7. Upgrade

    Upgrade redhat/python-galaxy-ng to a version that resolves this vulnerability.

    Fixed in 0:4.2.2-1.el7
  8. Upgrade

    Upgrade redhat/python-pulp-ansible to a version that resolves this vulnerability.

    Fixed in 1:0.5.6-1.el7
  9. Upgrade

    Upgrade redhat/automation-hub to a version that resolves this vulnerability.

    Fixed in 0:4.2.2-1.el8
  10. Upgrade

    Upgrade redhat/python3-django to a version that resolves this vulnerability.

    Fixed in 0:2.2.18-1.el8
  11. Upgrade

    Upgrade redhat/python-bleach to a version that resolves this vulnerability.

    Fixed in 0:3.3.0-1.el8
  12. Upgrade

    Upgrade redhat/python-bleach-allowlist to a version that resolves this vulnerability.

    Fixed in 0:1.0.3-1.el8
  13. Upgrade

    Upgrade redhat/python-galaxy-importer to a version that resolves this vulnerability.

    Fixed in 0:0.2.15-1.el8
  14. Upgrade

    Upgrade redhat/python-galaxy-ng to a version that resolves this vulnerability.

    Fixed in 0:4.2.2-1.el8
  15. Upgrade

    Upgrade redhat/python-pulp-ansible to a version that resolves this vulnerability.

    Fixed in 1:0.5.6-1.el8
  16. Upgrade

    Upgrade redhat/resource-agents to a version that resolves this vulnerability.

    Fixed in 0:4.1.1-98.el8
  17. Upgrade

    Upgrade redhat/python27-babel to a version that resolves this vulnerability.

    Fixed in 0:0.9.6-10.el7
  18. Upgrade

    Upgrade redhat/python27-python to a version that resolves this vulnerability.

    Fixed in 0:2.7.18-3.el7
  19. Upgrade

    Upgrade redhat/python27-python-jinja2 to a version that resolves this vulnerability.

    Fixed in 0:2.6-16.el7
  20. Upgrade

    Upgrade redhat/python27-python-pygments to a version that resolves this vulnerability.

    Fixed in 0:1.5-5.el7
  21. Upgrade

    Upgrade debian/mediawiki to a version that resolves this vulnerability.

    Fixed in 1:1.31.16-1+deb10u2Fixed in 1:1.31.16-1+deb10u6Fixed in 1:1.35.11-1~deb11u1Fixed in 1:1.35.13-1~deb11u1Fixed in 1:1.39.4-1~deb12u1Fixed in 1:1.39.5-1~deb12u1Fixed in 1:1.39.5-1
  22. Upgrade

    Upgrade debian/pygments to a version that resolves this vulnerability.

    Fixed in 2.3.1+dfsg-1+deb10u2Fixed in 2.7.1+dfsg-2.1Fixed in 2.14.0+dfsg-1Fixed in 2.15.1+dfsg-1
  23. Upgrade

    Upgrade ubuntu/pygments to a version that resolves this vulnerability.

    Fixed in 2.7.1+dfsg-2ubuntu1
  24. Upgrade

    Upgrade ubuntu/pygments to a version that resolves this vulnerability.

    Fixed in 2.2.0+dfsg-1ubuntu0.2
  25. Upgrade

    Upgrade ubuntu/pygments to a version that resolves this vulnerability.

    Fixed in 2.3.1+dfsg-1ubuntu2.2
  26. Upgrade

    Upgrade ubuntu/pygments to a version that resolves this vulnerability.

    Fixed in 2.3.1+dfsg-4ubuntu0.2
  27. Upgrade

    Upgrade ubuntu/pygments to a version that resolves this vulnerability.

    Fixed in 2.7.4
  28. Upgrade

    Upgrade ubuntu/pygments to a version that resolves this vulnerability.

    Fixed in 2.1+dfsg-1ubuntu0.2
  29. Upgrade

    Upgrade ubuntu/pygments to a version that resolves this vulnerability.

    Fixed in 1.6+dfsg-1ubuntu1.1+
  30. Upgrade

    Upgrade redhat/python-pygments to a version that resolves this vulnerability.

    Fixed in 2.7.4
  31. Upgrade

    Upgrade pip/Pygments to a version that resolves this vulnerability.

    Fixed in 2.7.4
  32. Upgrade

    Upgrade pygments to a version that resolves this vulnerability.

    Fixed in 2.7.4

Event History

Jan 11, 2021
CVE Published
12:00 AM
Mar 17, 2021
CVE Published
via MITRE·12:31 PM
Data Sourced
via MITRE·12:31 PM
Description
Mar 24, 2021
Data Sourced
via Microsoft·07:00 AM
DescriptionSeverityWeaknessAffected Software
Mar 29, 2021
Advisory Published
via GitHub·04:33 PM

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is the vulnerability ID?

The vulnerability ID is CVE-2021-27291.

2

What is the severity of CVE-2021-27291?

CVE-2021-27291 has a severity value of 7, which is considered high.

3

What is the description of CVE-2021-27291?

CVE-2021-27291 is a denial of service attack against pygments where specially crafted input files can cause the software to take infinite time to parse, consuming CPU resources.

4

How do I fix CVE-2021-27291?

To fix CVE-2021-27291, update your pygments package to version 2.7.4.

5

Where can I find more information about CVE-2021-27291?

You can find more information about CVE-2021-27291 in the references provided: 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

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