Non-constant-time comparison in PBKDF2-SHA256 password verification

Summary

A flaw was found in 389 Directory Server. The PBKDF2-SHA256 password verification function uses standard memcmp() for comparing password hashes instead of a constant-time comparison function. A remote attacker could potentially use timing measurements of LDAP bind attempts to infer partial hash information, though practical exploitation is extremely difficult due to PBKDF2 computational overhead. Red Hat severity: Low — CVSS 3.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N). Weakness: CWE-208. Affected Red Hat products: Red Hat Directory Server 11; Red Hat Directory Server 12; Red Hat Directory Server 13; Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9. Red Hat lists Red Hat Enterprise Linux 6 as not affected. Red Hat does not currently list a fixing RHSA for this CVE.