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    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.

    Published:Jan 11, 2021
    Last Modified:Nov 21, 2024
    EPS:Mar 17, 2021
    EPSS Score:0.02326
    CVSS Score:7.5

    Affected Products

    Vendor
    Debian
    Product
    Debian Linux
    Vendor
    Fedoraproject
    Product
    Fedora
    Vendor
    Pygments
    Product
    Pygments
    Vendor
    Redhat
    Product
    Ansible Automation Platform
    Vendor
    Redhat
    Product
    Enterprise Linux
    Vendor
    Redhat
    Product
    Rhel Software Collections

    Exploits

    https://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5cehttps://gist.github.com/b-c-ds/b1a2cc0c68a35c57188575eb496de5ce

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    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
    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

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High