CVE-2016-4423

7.5 HIGH
Published: June 01, 2016 Modified: May 06, 2026
View on NVD

Description

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
http://www.debian.org/security/2016/dsa-3588
Source: af854a3a-2127-422b-91ae-364da2661108
https://github.com/symfony/symfony/pull/18733
Source: af854a3a-2127-422b-91ae-364da2661108
https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory

6 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
1.4%
81th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

sensiolabs debian