Denial of Service via Username Length in Symfony Authentication

CVE-2016-4423 · MEDIUM Severity

AV:N/AC:L/AU:N/C:N/I:N/A:P

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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