{"id":"CVE-2016-4423","aliases":["DEBIAN-CVE-2016-4423","DSA-3588-1","EUVD-2022-5580","GHSA-whgv-8cg3-7hcm","UBUNTU-CVE-2016-4423"],"status":"published","title":"Symphony Denial of Service Via Overlong Usernames","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.","severity":{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-07","score":0.01862,"percentile":0.79382,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-399"],"published":"2016-05-29T00:00:00Z","modified":"2026-10-24T10:48:17Z","fixes":[{"ecosystem":"Packagist","package":"symfony/security-http","fixed_in":["2.3.41","2.7.13","2.8.6","3.0.6"],"sources":["ghsa","osv"]},{"ecosystem":"Packagist","package":"symfony/security","fixed_in":["2.3.41","2.7.13","2.8.6","3.0.6"],"sources":["ghsa","osv"]},{"ecosystem":"Packagist","package":"symfony/symfony","fixed_in":["2.3.41","2.7.13","2.8.6","3.0.6"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:12","package":"symfony","fixed_in":["2.8.6+dfsg-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"symfony","fixed_in":["2.8.6+dfsg-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"symfony","fixed_in":["2.8.6+dfsg-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.3.0"},{"fixed":"2.3.41"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.4.0"},{"fixed":"2.7.13"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.8.0"},{"fixed":"2.8.6"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.0.6"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.3.0"},{"fixed":"2.3.41"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.4.0"},{"fixed":"2.7.13"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.8.0"},{"fixed":"2.8.6"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/security","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.0.6"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.3.0"},{"fixed":"2.3.41"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.4.0"},{"fixed":"2.7.13"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.8.0"},{"fixed":"2.8.6"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"symfony/symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.0.6"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.8.6+dfsg-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.8.6+dfsg-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.8.6+dfsg-1"}]}]},{"source":"osv","ecosystem":"Debian:8","package":"symfony","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.3.21+dfsg-4+deb8u3"}]}],"versions":["2.3.21+dfsg-4","2.3.21+dfsg-4+deb8u1","2.3.21+dfsg-4+deb8u2"],"bundled":2},{"source":"osv","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.3.0"},{"fixed":"2.3.41"}]}]},{"source":"osv","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.4.0"},{"fixed":"2.7.13"}]}],"versions":["v2.4.0","v2.4.1","v2.4.10","v2.4.2","v2.4.3","v2.4.4","v2.4.5","v2.4.6","v2.4.7","v2.4.8","v2.4.9","v2.5.0","v2.5.0-BETA1","v2.5.0-BETA2","v2.5.0-RC1","v2.5.1","v2.5.10","v2.5.11","v2.5.12","v2.5.2","v2.5.3","v2.5.4","v2.5.5","v2.5.6","v2.5.7","v2.5.8","v2.5.9","v2.6.0","v2.6.0-BETA1","v2.6.0-BETA2","v2.6.1","v2.6.10","v2.6.11","v2.6.12","v2.6.13","v2.6.2","v2.6.3","v2.6.4","v2.6.5","v2.6.6","v2.6.7","v2.6.8","v2.6.9","v2.7.0","v2.7.0-BETA1","v2.7.0-BETA2","v2.7.1","v2.7.10","v2.7.11","v2.7.12","v2.7.2","v2.7.3","v2.7.4","v2.7.5","v2.7.6","v2.7.7","v2.7.8","v2.7.9"]},{"source":"osv","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.8.0"},{"fixed":"2.8.6"}]}],"versions":["v2.8.0","v2.8.1","v2.8.2","v2.8.3","v2.8.4","v2.8.5"]},{"source":"osv","ecosystem":"Packagist","package":"symfony/security-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0"},{"fixed":"3.0.6"}]}],"versions":["v3.0.0","v3.0.1","v3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usernames.","status":"published","published":"2016-06-01T22:59:02.457Z","modified":"2026-09-22T07:01:17.21704068Z","cvss":[{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:27.627285Z"},{"id":"GHSA-whgv-8cg3-7hcm","title":"Symphony Denial of Service Via Overlong Usernames","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.","status":"published","published":"2022-05-17T03:54:47Z","modified":"2024-12-08T05:43:41.795128Z","cvss":[{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:46:58.767335Z"},{"id":"UBUNTU-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.","status":"published","published":"2016-06-01T22:59:00Z","modified":"2025-10-24T04:45:45Z","cvss":[{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:12.261906Z"},{"id":"DSA-3588-1","title":"symfony - security update","status":"published","published":"2016-05-29T00:00:00Z","modified":"2026-03-09T01:21:36.236362Z","updated_at":"2026-11-02T15:46:16.199525Z"}]}}