UBUNTU-CVE-2020-28493

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    UBUNTU-CVE-2020-28493

    Published: 1 Feb 2021Last Modified: 4 Feb 2026
    Upstream:
    CVE-2020-28493

    Summary:

    Details: This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the `_punctuation_re regex` operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

    References: https://ubuntu.com/security/CVE-2020-28493, https://github.com/pallets/jinja/blob/ab81fd9c277900c85da0c322a2ff9d68a235b2e6/src/jinja2/utils.py%23L20, https://github.com/pallets/jinja/pull/1343, https://snyk.io/vuln/SNYK-PYTHON-JINJA2-1012994, https://github.com/yetingli/PoCs/tree/main/CVE-2020-28493, https://ubuntu.com/security/notices/USN-5701-1, https://ubuntu.com/security/notices/USN-6599-1, https://www.cve.org/CVERecord?id=CVE-2020-28493

    Affected packages

    Package

    Name: jinja2

    Purl: pkg:deb/ubuntu/[email protected]~esm2?arch=source&distro=trusty/esm

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -2.7.2-2ubuntu0.1~esm2

    Affected versions

    2.7-3

    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
    UBUNTU-CVE-2020-28493 | CVE-DB