CVE-2011-5121 in Internet Security
Summary
by MITRE
The Antivirus component in Comodo Internet Security before 5.3.175888.1227 does not properly check whether unspecified X.509 certificates are revoked, which has unknown impact and remote attack vectors.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/26/2018
The vulnerability identified as CVE-2011-5121 resides within the antivirus component of Comodo Internet Security, specifically affecting versions prior to 5.3.175888.1227. This flaw represents a critical weakness in the certificate validation process that could potentially allow malicious actors to bypass security controls. The issue stems from inadequate verification of X.509 certificate revocation status, creating a window of opportunity for attackers to exploit the system's trust mechanisms.
The technical flaw manifests in the improper handling of certificate revocation checks within Comodo's antivirus framework. X.509 certificates form the backbone of secure communications and digital identity verification, with certificate revocation lists serving as essential mechanisms to invalidate compromised or expired certificates. When security software fails to properly validate certificate status, it creates a trust gap that adversaries can exploit to present fraudulent certificates as legitimate. This vulnerability specifically affects the certificate checking process, which is fundamental to preventing man-in-the-middle attacks and ensuring secure network communications.
The operational impact of this vulnerability extends beyond simple certificate validation failures, as it creates potential attack vectors that could be leveraged for remote exploitation. Attackers could potentially use this weakness to establish fraudulent secure connections, bypass SSL/TLS protections, or impersonate legitimate services. The unspecified nature of the attack vectors suggests that the vulnerability could be exploited across multiple scenarios, including web browsing, email security, and network communications. This lack of specificity in the attack surface makes the vulnerability particularly dangerous as it could be weaponized in various attack scenarios without clear indication of its full scope.
The vulnerability aligns with CWE-295, which addresses improper certificate validation, and represents a significant weakness in the certificate trust model implementation. From an ATT&CK perspective, this vulnerability could be leveraged as part of initial access or persistence phases, potentially enabling attackers to establish covert communication channels or bypass network security controls. The weakness directly impacts the security posture of systems relying on Comodo's antivirus protection, as it undermines the fundamental trust mechanisms that secure communications depend upon.
Mitigation strategies should focus on immediate software updates to versions 5.3.175888.1227 or later, which contain the necessary certificate validation fixes. Organizations should also implement additional monitoring for suspicious certificate usage patterns and consider deploying supplementary security controls to detect potential exploitation attempts. Network segmentation and enhanced certificate monitoring tools can provide additional layers of protection while the primary vulnerability is addressed. Regular security assessments should verify that certificate validation mechanisms are functioning correctly and that no unauthorized certificate installations have occurred within the affected systems.