CVE-2021-3733

    Dashboard / Vulnerabilities / CVE-2021-3733

    CVE-2021-3733

    Published: 10 Mar 2022Last Modified: 20 Oct 2026

    Summary:

    Details: There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability.

    References: https://cert-portal.siemens.com/productcert/html/ssa-398330.html, https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html, https://lists.debian.org/debian-lts-announce/2023/06/msg00039.html, https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html, https://security.netapp.com/advisory/ntap-20220407-0001/, https://bugzilla.redhat.com/show_bug.cgi?id=1995234, https://bugs.python.org/issue43075, https://github.com/python/cpython/commit/7215d1ae25525c92b026166f9d5cac85fb, https://github.com/python/cpython/pull/24391, https://ubuntu.com/security/CVE-2021-3733

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -9a0099d1bf14bce417370aae6d55527417cda354

    Affected versions

    3.10.0-NA

    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
    CVE-2021-3733 | CVE-DB