CVE-2011-2487 in JBoss Enterprise Application Platform
Summary
by MITRE
The implementations of PKCS#1 v1.5 key transport mechanism for XMLEncryption in JBossWS and Apache WSS4J before 1.6.5 is susceptible to a Bleichenbacher attack.
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Analysis
by VulDB Data Team • 04/22/2021
The vulnerability described in CVE-2011-2487 represents a critical security flaw in the implementation of PKCS#1 v1.5 key transport mechanism within XML encryption libraries used in enterprise web services. This weakness specifically affects JBossWS and Apache WSS4J components prior to version 1.6.5, where the cryptographic implementation fails to properly validate encrypted key structures, creating a pathway for sophisticated cryptographic attacks. The flaw resides in how these systems handle the padding verification process during RSA encryption operations, which directly impacts the security of XML-based web service communications that rely on encrypted key transport.
The technical exploitation of this vulnerability stems from the implementation's failure to properly check padding integrity during the decryption process, making it susceptible to the Bleichenbacher attack pattern that targets the PKCS#1 v1.5 padding scheme. This attack leverages timing differences and error responses to gradually recover the plaintext RSA encrypted key through a series of carefully crafted queries. The vulnerability operates at the cryptographic protocol level, specifically targeting the RSA encryption padding validation mechanism that should ensure proper key structure formatting. According to CWE-327, this represents a weakness in a cryptographic algorithm that allows for the compromise of key material through side-channel analysis and timing attacks.
The operational impact of this vulnerability extends beyond simple data confidentiality breaches, as it can lead to complete system compromise when attackers successfully recover encrypted session keys or private keys used in web service communications. Organizations using affected versions of JBossWS and Apache WSS4J face significant risk of unauthorized access to sensitive data transmitted through XML-based web services, particularly in financial, healthcare, and government sectors where such communications are prevalent. The attack can be executed remotely without requiring authentication, making it particularly dangerous for web service endpoints that handle confidential information. This vulnerability directly aligns with ATT&CK technique T1566.001, which involves credential access through exploitation of cryptographic weaknesses in network services.
Mitigation strategies for this vulnerability require immediate patching of affected components to versions 1.6.5 or later, which contain proper padding validation mechanisms that prevent the Bleichenbacher attack vectors. Organizations should also implement additional security controls such as monitoring for unusual cryptographic operation patterns and ensuring proper error handling that does not leak timing information. The fix addresses the core implementation issue by adding proper padding validation checks that verify the integrity of the encrypted key structure before proceeding with decryption operations. Security teams should also consider implementing network segmentation and access controls around web service endpoints to limit the potential impact of successful exploitation attempts. This vulnerability underscores the importance of proper cryptographic implementation and the necessity of following established security standards such as those defined in NIST SP 800-57 for key management and cryptographic protocol design.