CVE-2015-1169 in Central Authentication Service
Summary
by MITRE
Apereo Central Authentication Service (CAS) Server before 3.5.3 allows remote attackers to conduct LDAP injection attacks via a crafted username, as demonstrated by using a wildcard and a valid password to bypass LDAP authentication.
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Analysis
by VulDB Data Team • 04/16/2022
The vulnerability identified as CVE-2015-1169 affects Apereo Central Authentication Service (CAS) Server versions prior to 3.5.3, presenting a critical security risk that enables remote attackers to conduct LDAP injection attacks through manipulated username inputs. This flaw resides in the authentication processing mechanism where the system fails to properly sanitize user-provided input before incorporating it into LDAP search queries, creating a pathway for malicious actors to bypass authentication controls.
The technical exploitation of this vulnerability occurs when an attacker crafts a specially formatted username containing LDAP special characters, particularly wildcards, which are then processed without adequate sanitization or escaping. When the CAS server attempts to authenticate users against an LDAP directory, the malformed username gets directly embedded into the LDAP search filter, allowing the attacker to manipulate the search query logic. The demonstration of this attack vector involves using a wildcard character in the username combined with a valid password, which causes the LDAP server to return positive authentication results even when the attacker does not possess the legitimate credentials for the target account.
This vulnerability directly maps to CWE-94, which describes improper neutralization of special elements used in an OS command, and more specifically to CWE-74, which addresses improper neutralization of special elements within input data. The attack pattern aligns with ATT&CK technique T1190, known as "Exploit Public-Facing Application," where adversaries target vulnerable web applications to gain unauthorized access. The impact extends beyond simple authentication bypass, as successful exploitation could lead to unauthorized access to protected resources, data breaches, and potential lateral movement within the network infrastructure that relies on CAS for authentication services.
Organizations utilizing affected CAS versions face significant operational risks, particularly in environments where CAS serves as a central authentication point for multiple applications and services. The vulnerability undermines the fundamental security model of the authentication system, potentially allowing attackers to enumerate valid users, access restricted resources, and compromise sensitive information. The attack requires minimal technical expertise to execute, making it particularly dangerous as it can be exploited by both skilled attackers and automated tools. Remediation efforts must include immediate patching to CAS Server version 3.5.3 or later, along with comprehensive input validation and sanitization measures. Additional mitigations should involve implementing proper LDAP query parameterization, monitoring for suspicious authentication patterns, and conducting regular security assessments of authentication infrastructure to prevent similar vulnerabilities in other components of the authentication ecosystem.