CVE-2012-5782 in Flexible Payments Service
Summary
by MITRE
Amazon Flexible Payments Service (FPS) PHP Library 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, related to misinterpretation of a certain "true" value.
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Analysis
by VulDB Data Team • 02/06/2018
The vulnerability identified as CVE-2012-5782 affects the Amazon Flexible Payments Service FPS PHP Library, representing a critical SSL/TLS security flaw that undermines the integrity of secure communications. This issue stems from improper certificate validation mechanisms within the library's implementation, specifically failing to perform adequate hostname verification during SSL handshake processes. The flaw allows attackers to execute successful man-in-the-middle attacks by presenting arbitrary valid SSL certificates that appear legitimate to the vulnerable system, thereby compromising the confidentiality and integrity of sensitive payment data transmitted through the service.
The technical root cause of this vulnerability lies in the library's failure to properly validate the server certificate against the expected hostname, a fundamental security practice that should be enforced during SSL/TLS connections. According to CWE-295, this represents a certificate validation weakness where the system does not properly verify that the certificate presented by the server matches the domain name being accessed. The vulnerability specifically relates to the improper handling of the subjectAltName field and Common Name field within X.509 certificates, where the library accepts certificates that contain valid signatures but do not match the expected server hostname. This misinterpretation of certificate validation logic allows attackers to exploit the trust relationship between client and server by substituting their own valid certificates in place of legitimate ones.
The operational impact of this vulnerability extends beyond simple data interception, as it fundamentally compromises the security model of payment processing systems that rely on the Amazon FPS service. Attackers can exploit this weakness to redirect payment transactions to fraudulent endpoints, potentially stealing sensitive customer payment information, personal identifiers, and financial data. The vulnerability affects systems that process payments through the FPS PHP library, making it particularly dangerous for e-commerce platforms, payment processors, and any service that integrates with Amazon's payment infrastructure. The implications are severe given that the library handles sensitive financial transactions, and the vulnerability could enable attackers to manipulate payment flows and redirect funds to unauthorized recipients.
Mitigation strategies for CVE-2012-5782 should focus on implementing proper SSL certificate validation mechanisms that enforce hostname matching against both the Common Name and subjectAltName fields of X.509 certificates. Organizations should upgrade to patched versions of the Amazon FPS PHP library that correctly implement certificate validation procedures, ensuring that all certificate verification processes include proper hostname checks. System administrators should also implement additional security controls such as certificate pinning, where specific certificate fingerprints are hardcoded into applications to prevent substitution attacks. According to ATT&CK framework tactic TA0011 (Command and Control), this vulnerability represents a significant opportunity for adversaries to establish persistent access through credential theft and data exfiltration, making immediate remediation essential. The fix should include comprehensive testing of SSL validation logic to ensure that all certificate verification processes properly enforce hostname matching, preventing attackers from exploiting this weakness to compromise payment processing systems and customer financial data.