CVE-2017-7080 in tvOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11 is affected. macOS before 10.13 is affected. tvOS before 11 is affected. watchOS before 4 is affected. The issue involves the "Security" component. It allows remote attackers to bypass intended certificate-trust restrictions via a revoked X.509 certificate.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/20/2021
The vulnerability identified as CVE-2017-7080 represents a critical certificate validation flaw within Apple's security infrastructure affecting multiple operating systems including iOS, macOS, tvOS, and watchOS. This issue resides within the Security component of Apple's software stack and fundamentally compromises the certificate trust verification mechanisms that are essential for secure communication and authentication processes. The vulnerability specifically allows remote attackers to bypass intended certificate-trust restrictions through the use of revoked X.509 certificates, undermining the core security assumptions that protect users from man-in-the-middle attacks and unauthorized access to sensitive resources.
The technical flaw stems from improper validation of certificate revocation status during the SSL/TLS handshake process and certificate chain verification procedures. When a certificate is revoked, it should be immediately rejected by the trust validation system, but this vulnerability enables attackers to present revoked certificates that are accepted as valid by the affected Apple operating systems. This occurs because the security subsystem fails to properly check the Certificate Revocation List (CRL) or Online Certificate Status Protocol (OCSP) responses before accepting certificates as trustworthy. The flaw essentially creates a pathway for attackers to establish secure-looking connections with malicious servers while appearing to present legitimate certificates, thereby circumventing the fundamental security controls designed to prevent such attacks.
The operational impact of this vulnerability is significant across multiple threat vectors and attack scenarios. Remote attackers can exploit this weakness to perform man-in-the-middle attacks against HTTPS connections, SSL/TLS services, and other certificate-based authentication systems. This vulnerability particularly affects secure web browsing, email communications, and any service that relies on X.509 certificate validation for establishing trust. The implications extend to corporate environments where employees might unknowingly connect to malicious servers that present revoked certificates, potentially leading to data exfiltration, credential theft, or system compromise. The vulnerability also impacts the integrity of secure communications channels, as users cannot rely on certificate validation to ensure they are connecting to legitimate services.
Mitigation strategies for CVE-2017-7080 primarily focus on immediate system updates and enhanced monitoring protocols. Apple released security updates for iOS 11, macOS 10.13, tvOS 11, and watchOS 4 that address this vulnerability by implementing proper certificate revocation checking mechanisms. Organizations should prioritize deployment of these updates across all affected systems and verify that certificate validation is functioning correctly through automated testing procedures. Additional defensive measures include implementing network monitoring to detect unusual certificate validation patterns, deploying certificate pinning mechanisms where appropriate, and establishing enhanced logging of SSL/TLS handshake activities to identify potential exploitation attempts. From a cybersecurity framework perspective, this vulnerability aligns with CWE-295 Certificate Validation Issues and represents a technique that could be categorized under ATT&CK tactic T1552.001 for credentials in files and T1071.002 for application layer protocols. The vulnerability demonstrates the critical importance of proper certificate management and the potential consequences when certificate validation systems fail to properly enforce revocation status checks, emphasizing the need for robust certificate lifecycle management practices within enterprise security architectures.