Symphony Denial of Service Via Overlong Usernames
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HIGH
GHSA-whgv-8cg3-7hcm
CVE-2016-4423
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.
Affected Packages
| Ecosystem | Package | Vulnerable Versions | Patched Version |
|---|---|---|---|
| packagist |
symfony/symfony
|
>= 3.0.0, < 3.0.6>= 2.8.0, < 2.8.6>= 2.4.0, < 2.7.13>= 2.3.0, < 2.3.41 |
3.0.6
|
| packagist |
symfony/security
|
>= 3.0.0, < 3.0.6>= 2.8.0, < 2.8.6>= 2.4.0, < 2.7.13>= 2.3.0, < 2.3.41 |
3.0.6
|
| packagist |
symfony/security-http
|
>= 3.0.0, < 3.0.6>= 2.8.0, < 2.8.6>= 2.4.0, < 2.7.13>= 2.3.0, < 2.3.41 |
3.0.6
|
Actions
Advisory Details
| Published: | May 17, 2022 about 4 years ago |
| Updated: | June 18, 2026 about 15 hours ago |
| CVSS Score: | 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| EPSS: | 1.44% 81th percentile |
| Source: | Github |
| Classification: | GENERAL |
| UUID: | GSA_kwCzR0hTQS13aGd2LThjZzMtN2hjbc4AAdU9 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2016-4423
- https://github.com/symfony/symfony/pull/18733
- https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session
- http://www.debian.org/security/2016/dsa-3588
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2016-4423.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security/CVE-2016-4423.yaml
- https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2016-4423.yaml
- https://symfony.com/cve-2016-4423
- https://github.com/advisories/GHSA-whgv-8cg3-7hcm