CVE-2014-3584 in CXF
Summary
by MITRE
The SamlHeaderInHandler in Apache CXF before 2.6.11, 2.7.x before 2.7.8, and 3.0.x before 3.0.1 allows remote attackers to cause a denial of service (infinite loop) via a crafted SAML token in the authorization header of a request to a JAX-RS service.
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Analysis
by VulDB Data Team • 06/10/2017
The vulnerability identified as CVE-2014-3584 represents a critical denial of service flaw affecting Apache CXF implementations across multiple version ranges. This issue specifically targets the SamlHeaderInHandler component within the CXF framework, which processes SAML tokens in authorization headers for JAX-RS services. The flaw enables remote attackers to trigger an infinite loop condition through the careful crafting of malicious SAML tokens, effectively rendering the targeted services unavailable to legitimate users. The vulnerability exists in versions prior to 2.6.11, 2.7.8, and 3.0.1, indicating a widespread impact across the Apache CXF ecosystem. The SamlHeaderInHandler processes incoming SAML assertions within the HTTP authorization header, making it a prime target for denial of service attacks that can disrupt service availability.
The technical exploitation of this vulnerability occurs when a crafted SAML token contains malformed or specially constructed elements that cause the SamlHeaderInHandler to enter an infinite loop during token processing. This loop typically stems from improper validation of SAML assertion structures, particularly around the handling of nested elements or recursive references within the token. When the handler attempts to parse and validate the malicious SAML token, it encounters structures that cause the processing logic to repeatedly iterate without proper termination conditions. The vulnerability manifests as a resource exhaustion attack where CPU cycles are consumed indefinitely, preventing the service from processing legitimate requests. This behavior aligns with CWE-835, which describes infinite loops in software implementations. The attack vector requires only a single malicious request to the JAX-RS endpoint, making it particularly dangerous as it can be executed remotely without requiring authentication or privileged access.
The operational impact of CVE-2014-3584 extends beyond simple service disruption, creating significant business continuity risks for organizations relying on Apache CXF for their web services infrastructure. When exploited, the infinite loop causes the affected service to become unresponsive, potentially leading to cascading failures in dependent systems and applications that rely on the vulnerable endpoints. The vulnerability affects both SOAP and RESTful services within the CXF framework, as it operates at the handler level rather than being specific to a particular service type. Organizations using JAX-RS services with SAML authentication mechanisms face the highest risk, as these endpoints become completely inaccessible to legitimate users. The attack can be executed repeatedly, allowing an attacker to maintain the denial of service condition until the service is manually restarted or the system is rebooted.
Mitigation strategies for CVE-2014-3584 primarily involve upgrading to patched versions of Apache CXF where the SamlHeaderInHandler has been modified to properly validate SAML token structures and prevent infinite loop conditions. Organizations should prioritize upgrading to versions 2.6.11, 2.7.8, or 3.0.1, depending on their current implementation. Additional protective measures include implementing request rate limiting and monitoring for unusual processing patterns that might indicate an ongoing attack. Network-level firewalls and intrusion detection systems can be configured to detect and block malformed SAML tokens that exhibit characteristics consistent with the vulnerability. The fix implemented by Apache CXF developers addresses the root cause by adding proper bounds checking and loop termination conditions within the token parsing logic. This aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates the importance of proper input validation in preventing resource exhaustion vulnerabilities. Organizations should also implement comprehensive testing procedures to verify that patched versions properly handle edge cases in SAML token processing and maintain service availability under various attack conditions.