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High

Symphony Denial of Service Via Overlong Usernames

  • Disclosed: 17.05.2022
  • Updated: 11.10.2026 10:22

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 software

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PlatformPackageVulnerable versionsFixed in
Composer package symfony/security >= 2.3.0, < 2.3.41, >= 2.4.0, < 2.7.13, >= 2.8.0, < 2.8.6, >= 3.0.0, < 3.0.6 2.3.41, 2.7.13, 2.8.6, 3.0.6
Composer package symfony/security-http >= 2.3.0, < 2.3.41, >= 2.4.0, < 2.7.13, >= 2.8.0, < 2.8.6, >= 3.0.0, < 3.0.6 2.3.41, 2.7.13, 2.8.6, 3.0.6
Composer package symfony/symfony >= 2.3.0, < 2.3.41, >= 2.4.0, < 2.7.13, >= 2.8.0, < 2.8.6, >= 3.0.0, < 3.0.6 2.3.41, 2.7.13, 2.8.6, 3.0.6

References

CVSS score 7.5/10
CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
-
Platform
Composer
Package
symfony/security, symfony/security-http, symfony/symfony
Disclosed
17.05.2022
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-whgv-8cg3-7hcm - CC BY 4.0

Vulnerability history: symfony/security

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (17) in the archive
Total entries
17
First → latest
02.2020 05.2022
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 3
  • High 7
  • Medium 6
  • Low 1

Disclosures per year

Severity:
  1. Symfony Incorrect Access Control
    Critical · 9.8 CVE-2017-11365 >= 2.7.30, < 2.7.32, >= 2.8.23, < 2.8.25, >= 3.2.10, < 3.2.12, >= 3.3.3, < 3.3.5 2.7.32, 2.8.25, 3.2.12, 3.3.5
  2. Symphony Denial of Service Via Overlong Usernames this entry
    High · 7.5 CVE-2016-4423 >= 2.3.0, < 2.3.41, >= 2.4.0, < 2.7.13, >= 2.8.0, < 2.8.6, >= 3.0.0, < 3.0.6 2.3.41, 2.7.13, 2.8.6, 3.0.6
  3. Symfony Cryptographic Vulnerability
    High · 7.5 CVE-2016-1902 >= 2.3.0, < 2.3.37, >= 2.4.0, < 2.6.13, >= 2.7.0, < 2.7.9 2.3.37, 2.6.13, 2.7.9
  4. Symfony Vulnerable to Timing Attack
    High CVE-2015-8125 >= 2.3.0, < 2.3.35, >= 2.4.0, < 2.6.12, >= 2.7.0, < 2.7.7 2.3.35, 2.6.12, 2.7.7
  5. Symfony Authentication Bypass
    Critical · 9.8 CVE-2018-11407 >= 2.8.0, < 2.8.37, >= 3.0.0, < 3.3.17, >= 3.4.0, < 3.4.7, >= 4.0.0, < 4.0.7 2.8.37, 3.3.17, 3.4.7, 4.0.7
  6. Symfony Authentication Bypass
    Critical · 9.8 CVE-2016-2403 >= 2.8.0, < 2.8.6, >= 3.0.0, < 3.0.6 2.8.6, 3.0.6
  7. Symfony Session Fixation Vulnerability
    High · 8.1 CVE-2018-11385 >= 2.7.0, < 2.7.48, >= 2.8.0, < 2.8.41, >= 3.0.0, < 3.3.17, >= 3.4.0, < 3.4.11, >= 4.0.0, < 4.0.11 2.7.48, 2.8.41, 3.3.17, 3.4.11, 4.0.11
  8. Symfony CSRF Token Fixation
    High · 8.8 CVE-2018-11406 >= 2.7.0, < 2.7.48, >= 2.8.0, < 2.8.41, >= 3.0.0, < 3.3.17, >= 3.4.0, < 3.4.11, >= 4.0.0, < 4.0.11 2.7.48, 2.8.41, 3.3.17, 3.4.11, 4.0.11
  9. Firewall configured with unanimous strategy was not actually unanimous in Symfony
    High · 7.6 CVE-2020-5275 >= 4.4.0, < 4.4.7, >= 5.0.0, < 5.0.7 4.4.7, 5.0.7
  10. Improper authentication in Symfony
    High · 7.5 CVE-2019-10911 >= 2.7.0, < 2.7.51, >= 2.8.0, < 2.8.50, >= 3.0.0, < 3.4.26, >= 4.0.0, < 4.1.12, >= 4.2.0, < 4.2.7 2.7.51, 2.8.50, 3.4.26, 4.1.12, 4.2.7

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