An issue was discovered in the Ldap component in Symfony 2.8.x before 2.8.37, 3.3.x before 3.3.17, 3.4.x before 3.4.7, and 4.0.x before 4.0.7. It allows remote attackers to bypass authentication by logging in with a "null" password and valid username, which triggers an unauthenticated bind. NOTE: this issue exists because of an incomplete fix for CVE-2016-2403.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
2.4% chance of exploitation in the next 30 days; higher than 83% of CVEs (scores of 2026-10-31)