CVE-2016-4423

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    CVE-2016-4423

    Published: 1 Jun 2016Last Modified: 7 Aug 2026

    Summary:

    Details: The attemptAuthentication function in Component/Security/Http/Firewall/UsernamePasswordFormAuthenticationListener.php in Symfony before 2.3.41, 2.7.x before 2.7.13, 2.8.x before 2.8.6, and 3.0.x before 3.0.6 does not limit the length of a username stored in a session, which allows remote attackers to cause a denial of service (session storage consumption) via a series of authentication attempts with long, non-existent usernames.

    References: http://www.debian.org/security/2016/dsa-3588, https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session, https://github.com/symfony/symfony/pull/18733

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- de2f3d51160791ef254010953dbde178fee9845f
    Fixed -None

    Affected versions

    2.7.0
    2.7.1
    2.7.10
    2.7.11
    2.7.12
    2.7.2
    2.7.3
    2.7.4
    2.7.5
    2.7.6
    2.7.7
    2.7.8
    2.7.9

    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