CVE-2010-4675 in ASA
Summary
by MITRE
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) do not properly determine the interfaces for which TELNET connections should be permitted, which allows remote authenticated users to bypass intended access restrictions via vectors involving the "lowest security level interface," aka Bug ID CSCsv40504.
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Analysis
by VulDB Data Team • 11/30/2024
The vulnerability identified as CVE-2010-4675 affects Cisco Adaptive Security Appliances (ASA) 5500 series devices operating with software versions prior to 8.2(3). This security flaw resides within the access control mechanisms of the ASA platform, specifically impacting how the device determines interface permissions for TELNET connections. The vulnerability represents a significant authorization bypass issue that could potentially allow malicious actors to gain unauthorized access to network infrastructure. The affected devices operate under the assumption that TELNET access restrictions are properly enforced across all interfaces, but a design flaw in the security level determination process creates an exploitable gap in the access control model.
The technical flaw manifests when the ASA device fails to correctly identify which interfaces should be permitted to accept TELNET connections based on their security levels. This occurs specifically when the device encounters an interface with the lowest security level in its configuration, causing the system to incorrectly grant TELNET access privileges that should be restricted. The vulnerability stems from improper interface validation during the TELNET connection establishment process, where the software does not adequately verify that TELNET access is only permitted on interfaces configured with appropriate security levels. This misconfiguration allows authenticated users to establish TELNET sessions on interfaces that should be restricted, effectively bypassing the intended security controls.
From an operational perspective, this vulnerability presents a serious risk to network security infrastructure as it enables remote authenticated attackers to circumvent access controls that are fundamental to protecting network devices. The impact extends beyond simple unauthorized access to potentially allowing attackers to modify device configurations, view sensitive network information, or establish persistent access points within the network. The vulnerability is particularly concerning because it affects the core security functionality of the ASA appliance, which serves as a critical network security boundary. Attackers could leverage this flaw to gain administrative privileges on the device, potentially leading to complete network compromise and unauthorized access to protected network segments.
The vulnerability aligns with CWE-284, which addresses improper access control issues in software systems, and demonstrates a clear failure in privilege management within the network security appliance. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and lateral movement, as it allows attackers to bypass access restrictions that would normally prevent unauthorized administrative access. Organizations utilizing affected ASA devices should immediately implement mitigation strategies including upgrading to software version 8.2(3) or later, implementing additional access controls, and monitoring for unauthorized TELNET access attempts. The recommended remediation approach involves comprehensive software patching combined with network segmentation strategies to limit the potential impact of such vulnerabilities. Security teams should also conduct thorough audits of their ASA configurations to ensure proper interface security level assignments and implement network monitoring to detect anomalous TELNET connection patterns that might indicate exploitation attempts.