CVE-2015-4211 in AnyConnect Secure Mobility Client
Summary
by MITRE
Cisco AnyConnect Secure Mobility Client 3.1(60) on Windows does not properly validate pathnames, which allows local users to gain privileges via a crafted INF file, aka Bug ID CSCus65862.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability CVE-2015-4211 represents a critical path traversal flaw in Cisco AnyConnect Secure Mobility Client version 3.1(60) for Windows operating systems. This issue stems from inadequate validation of pathname inputs during the installation process, creating a privilege escalation vector that can be exploited by local attackers. The vulnerability specifically affects the client-side installation mechanism that processes INF files, which are Windows installation information files used to configure device drivers and system components. When the AnyConnect client processes a crafted INF file, it fails to properly sanitize or validate the file paths, allowing an attacker to manipulate the installation process and potentially execute arbitrary code with elevated privileges.
The technical exploitation of this vulnerability occurs through the manipulation of INF file paths during the AnyConnect client installation process. The client application does not adequately validate or sanitize the pathname components within these installation files, which can lead to directory traversal attacks. An attacker can craft a malicious INF file that contains specially formatted paths designed to bypass normal security checks. This flaw falls under the Common Weakness Enumeration category CWE-22, which describes improper limitation of a pathname to a restricted directory, also known as path traversal or directory traversal. The vulnerability allows an attacker to specify arbitrary file paths that could potentially overwrite critical system files or install malicious components in privileged locations, ultimately enabling local privilege escalation from standard user level to administrative privileges.
From an operational impact perspective, this vulnerability poses significant security risks to organizations relying on Cisco AnyConnect for remote access and VPN connectivity. The local privilege escalation capability means that any user with access to the system can potentially elevate their privileges to administrator level, providing complete control over the affected machine. This creates a substantial risk for corporate environments where multiple users may have access to the same systems, as the vulnerability can be exploited without requiring network access or authentication credentials. The attack vector is particularly concerning because it requires only local system access, making it difficult to detect through traditional network monitoring or intrusion detection systems. According to the MITRE ATT&CK framework, this vulnerability maps to privilege escalation techniques under the T1068 category, specifically targeting local system access and privilege elevation through software exploitation.
The mitigation strategies for CVE-2015-4211 primarily focus on updating to patched versions of the Cisco AnyConnect Secure Mobility Client. Cisco released security updates that address this path validation issue by implementing proper input sanitization and pathname validation mechanisms. Organizations should immediately deploy the latest security patches available from Cisco, which include enhanced validation of INF file paths during installation processes. System administrators should also implement additional security measures such as restricting local user access to system installation directories and monitoring for unusual INF file processing activities. Network segmentation and least privilege principles should be enforced to minimize the potential impact of successful exploitation. Regular security assessments and vulnerability scanning should be conducted to identify systems running vulnerable versions of the AnyConnect client, with immediate remediation prioritized for high-risk environments. The vulnerability demonstrates the critical importance of input validation in client-side applications and highlights the need for comprehensive security testing of installation and update mechanisms in enterprise security solutions.