CVE-2015-2684 in Service Provider
Summary
by MITRE
Shibboleth Service Provider (SP) before 2.5.4 allows remote authenticated users to cause a denial of service (crash) via a crafted SAML message.
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Analysis
by VulDB Data Team • 11/27/2024
The vulnerability identified as CVE-2015-2684 affects the Shibboleth Service Provider component, a critical element in identity federation systems that enables single sign-on capabilities across multiple domains. This issue resides in versions prior to 2.5.4 of the Shibboleth SP software, which is widely deployed in enterprise environments and academic institutions for managing user authentication and authorization. The vulnerability represents a significant security concern as it allows authenticated attackers to disrupt service availability through carefully crafted SAML (Security Assertion Markup Language) messages, potentially compromising the reliability of identity federation services.
The technical flaw manifests in the improper handling of malformed SAML messages within the Shibboleth SP processing pipeline. When an authenticated user submits a specially crafted SAML assertion containing malformed or unexpected data structures, the service provider fails to properly validate or sanitize the input before processing. This leads to a buffer overflow condition or stack corruption that ultimately results in the service provider process crashing and terminating unexpectedly. The vulnerability specifically targets the XML parsing and validation mechanisms within the SP software, where insufficient bounds checking and error handling routines fail to account for maliciously constructed SAML payloads that could exploit memory management weaknesses in the underlying implementation.
The operational impact of this vulnerability extends beyond simple service disruption as it can be leveraged by attackers to systematically degrade the availability of authentication services within federated environments. Organizations relying on Shibboleth SP for identity management may experience unauthorized service interruptions that could affect multiple applications and systems dependent on the same authentication infrastructure. The remote nature of the attack means that adversaries need only valid credentials to access the service provider to execute the denial of service attack, making it particularly dangerous in environments where authentication credentials might be compromised through other means. This vulnerability directly maps to CWE-121, which addresses stack-based buffer overflow conditions, and represents a classic example of how insufficient input validation can lead to service disruption in identity management systems.
Mitigation strategies for CVE-2015-2684 primarily focus on immediate software updates to versions 2.5.4 or later, which contain proper input validation and error handling mechanisms. Organizations should also implement network-level monitoring to detect unusual patterns of SAML message processing that might indicate exploitation attempts, as well as establish robust incident response procedures for handling service disruptions. Additional defensive measures include implementing rate limiting on authentication requests and configuring proper logging to track SAML message processing activities. The vulnerability demonstrates the importance of maintaining up-to-date identity federation software and highlights the need for comprehensive security testing of authentication components. From an ATT&CK perspective, this vulnerability aligns with the T1499.004 technique for network denial of service, as it enables attackers to compromise service availability through targeted exploitation of authentication infrastructure. Organizations should also consider implementing multi-factor authentication and additional access controls to reduce the risk of authenticated users exploiting this vulnerability, while maintaining regular security assessments of their identity federation systems to identify similar weaknesses in other components.