CVE-2013-5561 in ASA CX Context-Aware Security
Summary
by MITRE
The Safe Search enforcement feature in Cisco Adaptive Security Appliance (ASA) CX Context-Aware Security Software does not properly perform filtering, which allows remote attackers to bypass intended policy restrictions via unspecified vectors, aka Bug ID CSCui94622.
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Analysis
by VulDB Data Team • 06/01/2021
The vulnerability identified as CVE-2013-5561 affects Cisco Adaptive Security Appliance (ASA) CX Context-Aware Security Software where the Safe Search enforcement feature fails to properly implement filtering mechanisms. This security flaw exists within the context-aware security framework that Cisco employs to monitor and control network traffic based on user context and device characteristics. The issue specifically impacts the enforcement of content filtering policies that are designed to restrict access to potentially inappropriate or harmful content, particularly within web browsing environments.
The technical implementation flaw resides in how the ASA CX software handles the Safe Search enforcement functionality, which is intended to filter web content and restrict access to explicit material. When properly functioning, this feature should enforce predetermined policies that limit access to certain categories of content based on user context and security requirements. However, the vulnerability allows attackers to circumvent these policy restrictions through unspecified attack vectors that exploit weaknesses in the filtering logic. The flaw essentially creates a bypass mechanism that enables unauthorized access to content that should be restricted by the security policies.
From an operational perspective, this vulnerability presents significant risks to organizations relying on Cisco ASA CX for network security enforcement. Remote attackers who successfully exploit this vulnerability can bypass content filtering policies that are critical for maintaining appropriate web usage standards, particularly in environments with strict compliance requirements or child protection policies. The impact extends beyond simple content access, as it could potentially allow attackers to reach malicious websites, access restricted resources, or circumvent other security controls that depend on proper filtering enforcement. Organizations may experience unauthorized access to inappropriate content, potential data leakage, or compromised network security posture.
The vulnerability aligns with CWE-284, which addresses inadequate access control mechanisms, and represents a failure in privilege enforcement within the security appliance. From an ATT&CK framework perspective, this weakness maps to techniques involving privilege escalation and evasion of security controls, as attackers can bypass the intended security restrictions without requiring elevated privileges. The unspecified vectors suggest that the attack surface may involve multiple approaches including protocol manipulation, session hijacking, or exploitation of configuration weaknesses that allow bypassing the filtering enforcement mechanisms.
Organizations should implement immediate mitigations including applying the latest security patches from Cisco, reviewing and strengthening content filtering policies, and monitoring network traffic for signs of exploitation attempts. Network administrators should also consider implementing additional layers of content filtering outside the ASA CX environment to provide defense-in-depth. The mitigation strategy should include regular security assessments of the context-aware security features and monitoring for unauthorized access attempts that may indicate exploitation of this vulnerability. Cisco recommends updating to the latest software versions that address this specific bypass vulnerability in the Safe Search enforcement feature.