CVE-2011-5241 in Services Twitter
Summary
by MITRE
Services_Twitter 0.6.3 does not verify that the server hostname matches a domain name in the subject s Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.
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Analysis
by VulDB Data Team • 02/05/2018
The vulnerability described in CVE-2011-5241 represents a critical SSL/TLS certificate validation flaw within the Services_Twitter library version 0.6.3. This issue stems from improper implementation of hostname verification during SSL/TLS certificate validation processes, creating a significant security weakness that directly violates established cryptographic security practices. The flaw specifically affects the library's ability to verify that the SSL certificate presented by a server corresponds to the expected domain name, leaving systems vulnerable to sophisticated man-in-the-middle attacks.
The technical root cause of this vulnerability lies in the library's failure to properly validate the subject hostname against the certificate's subject common name or subject alternative name fields. According to the x509 certificate standard and industry best practices outlined in CWE-295, proper hostname verification requires checking that the certificate's subject name matches the domain name being accessed. This validation is essential for maintaining the integrity of SSL/TLS connections and preventing attackers from establishing fraudulent secure connections using valid but unauthorized certificates. The Services_Twitter library's implementation bypasses this critical security check, allowing attackers to present any valid certificate without proper domain verification.
The operational impact of this vulnerability is severe and multifaceted, creating multiple attack vectors for malicious actors. Attackers can exploit this weakness to perform successful man-in-the-middle attacks by presenting valid SSL certificates that appear legitimate to the client application. This allows them to intercept, modify, or steal sensitive data transmitted between the client and server, including authentication credentials, personal information, and business-critical data. The vulnerability directly maps to ATT&CK technique T1041 which describes data manipulation during network communication, and represents a significant compromise of the confidentiality and integrity aspects of the CIA triad.
Security implications extend beyond immediate data interception to include potential credential theft, session hijacking, and broader system compromise. When applications using the affected Services_Twitter library establish SSL connections, they become vulnerable to attacks where malicious actors can seamlessly impersonate legitimate services. This vulnerability particularly impacts web applications that rely on Twitter API integrations, potentially allowing attackers to gain unauthorized access to user accounts, manipulate social media content, or harvest sensitive user information. The flaw undermines the fundamental trust model of SSL/TLS encryption, making it ineffective against determined attackers who can simply generate or obtain valid certificates for arbitrary domains.
Mitigation strategies for this vulnerability require immediate attention and include several remediation approaches. The most effective solution involves updating to a newer version of the Services_Twitter library that properly implements hostname verification according to RFC 2818 and RFC 6125 standards. Organizations should also implement additional security controls such as certificate pinning, where applications maintain a trusted list of certificate fingerprints to validate against, and regular security audits of SSL/TLS implementations. Network-level protections including intrusion detection systems and certificate transparency monitoring can help detect and prevent exploitation attempts. Furthermore, implementing proper security awareness training for developers and system administrators ensures that SSL/TLS certificate validation is properly understood and implemented across all application components, reducing the likelihood of similar vulnerabilities in future implementations.