CVE-2015-1796 in Identity Provider
Summary
by MITRE
The PKIX trust engines in Shibboleth Identity Provider before 2.4.4 and OpenSAML Java (OpenSAML-J) before 2.6.5 trust candidate X.509 credentials when no trusted names are available for the entityID, which allows remote attackers to impersonate an entity via a certificate issued by a shibmd:KeyAuthority trust anchor.
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Analysis
by VulDB Data Team • 05/23/2022
The vulnerability described in CVE-2015-1796 represents a critical flaw in the Public Key Infrastructure X.509 validation mechanisms used by Shibboleth Identity Provider and OpenSAML Java implementations. This weakness arises from the improper handling of certificate validation when no trusted names are available for entity identification, creating a dangerous trust path that adversaries can exploit to impersonate legitimate entities within the federation. The vulnerability specifically affects versions prior to 2.4.4 for Shibboleth Identity Provider and 2.6.5 for OpenSAML-J, indicating a widespread issue across implementations that rely on these components for identity federation and single sign-on operations.
The technical flaw stems from the PKIX trust engine's behavior when validating X.509 certificates against entity identifiers. When no trusted names are established for an entityID, the system defaults to trusting any candidate X.509 credential that passes basic validation checks, bypassing the normal certificate chain validation procedures that should ensure proper trust relationships. This creates a scenario where an attacker can present a certificate issued by a shibmd:KeyAuthority trust anchor and successfully impersonate any entity within the federation, as the system fails to properly validate the certificate's relationship to the target entity. The vulnerability operates at the certificate validation layer and directly impacts the integrity of the identity federation trust model.
The operational impact of this vulnerability is severe and far-reaching within identity federation environments. Attackers can exploit this weakness to gain unauthorized access to protected resources by impersonating legitimate service providers or identity providers within the federation. This compromise undermines the fundamental security assumptions of the federation architecture, potentially allowing attackers to access sensitive data, perform unauthorized transactions, or conduct man-in-the-middle attacks against legitimate communications. The vulnerability is particularly dangerous because it operates silently during authentication processes, making detection difficult and allowing attackers to maintain persistent access without immediate detection.
Mitigation strategies for CVE-2015-1796 require immediate patching of affected systems to versions 2.4.4 or later for Shibboleth Identity Provider and 2.6.5 or later for OpenSAML-J. Organizations should also implement additional validation measures such as explicit certificate name constraints, enhanced certificate revocation checking, and regular security audits of trust relationships within their federation environments. The vulnerability aligns with CWE-295 which addresses improper certificate validation, and maps to ATT&CK technique T1552.001 related to credentials from password storage devices, as it involves unauthorized access through compromised trust relationships. Security teams should also consider implementing network monitoring to detect anomalous certificate validation patterns and establish more robust certificate management policies that enforce strict validation requirements even when trusted names are not available.