CVE-2016-6369 in AnyConnect Secure Mobility Client
Summary
by MITRE
Cisco AnyConnect Secure Mobility Client before 4.2.05015 and 4.3.x before 4.3.02039 mishandles pathnames, which allows local users to gain privileges via a crafted INF file, aka Bug ID CSCuz92464.
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Analysis
by VulDB Data Team • 09/25/2024
The vulnerability identified as CVE-2016-6369 affects Cisco AnyConnect Secure Mobility Client versions prior to 4.2.05015 and 4.3.x versions before 4.3.02039. This issue represents a path manipulation flaw that enables local attackers to escalate privileges through maliciously crafted INF files. The vulnerability stems from inadequate validation of pathname handling within the client's installation and execution processes, creating a pathway for privilege escalation attacks. The affected software operates with elevated privileges during installation phases, making it a prime target for local privilege escalation exploits.
The technical flaw manifests in how the AnyConnect client processes INF files during installation or update operations. When processing these Windows installation files, the client fails to properly validate or sanitize pathname references, allowing attackers to manipulate file paths to execute arbitrary code with elevated privileges. This vulnerability specifically targets the installation service component that handles driver installations and system modifications, where proper input validation is critical. The issue falls under the category of improper input validation and path handling, aligning with CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') and CWE-78 - Improper Neutralization of Special Elements used in OS Command Injection.
The operational impact of this vulnerability is significant for organizations relying on Cisco AnyConnect for secure remote access. Local attackers with basic user privileges can leverage this flaw to gain system-level access, potentially leading to complete system compromise. Once escalated, attackers could access sensitive data, modify system configurations, install malware, or establish persistent backdoors. The vulnerability affects both the 4.2.x and 4.3.x release branches, indicating a widespread issue across multiple versions of the client software. This privilege escalation capability undermines the security model of the VPN client, as it allows unauthorized users to bypass normal access controls and gain administrative privileges on the target system.
Organizations should prioritize immediate patching of affected AnyConnect clients to address this vulnerability. The remediation involves updating to Cisco AnyConnect Secure Mobility Client versions 4.2.05015 or 4.3.02039, which contain proper pathname validation and sanitization mechanisms. Security administrators should conduct comprehensive inventory checks to identify all affected systems and ensure timely deployment of patches. Additional mitigations include implementing least privilege principles for user accounts, monitoring system logs for suspicious installation activities, and deploying endpoint protection solutions that can detect and block malicious INF file execution. The vulnerability demonstrates the critical importance of validating all input sources in privileged execution contexts, particularly in software that handles system-level modifications. Organizations should also consider implementing application whitelisting policies to restrict execution of unsigned or untrusted installation packages, aligning with defensive strategies outlined in the MITRE ATT&CK framework under the privilege escalation techniques.