Bug ID 1591549: Support for case-insensitive LDAP username lookup

Last Modified: Jun 14, 2025

Affected Product(s):
F5OS F5OS-A, F5OS-C(all modules)

Known Affected Versions:
F5OS-A 1.3.0, F5OS-A 1.3.1, F5OS-A 1.3.2, F5OS-A 1.4.0, F5OS-A 1.5.0, F5OS-A 1.5.1, F5OS-A 1.5.2, F5OS-A 1.5.3, F5OS-A 1.7.0, F5OS-A 1.8.0

Fixed In:
F5OS-C 1.8.0

Opened: Jun 04, 2024

Severity: 3-Major

Symptoms

Previously, username lookup for LDAP-authenticated users was always case-sensitive.

Impact

Username lookups for authentication/authorization against LDAP directory were always conducted in a case-sensitive fashion, even for directories where case-insensitive was the default for the organization (e.g. Windows AD). Case-insensitive default is considered a safer security posture. It prevents username masking and cache injection when multiple users that only differ by case, with differing authorization privileges, exist in the same directory.

Conditions

Third-party authentication is configured with LDAP or Active Directory; user(s) in question reside in LDAP directory.

Workaround

Always use correct case for case-sensitive searches.

Fix Information

A new option was added which allows the admin to enable case-insensitive searches for LDAP username lookups. Note that case-sensitive remains the default for security reasons.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips