CVE-2015-0665 in AnyConnect Secure Mobility Client
Summary
by MITRE
The Hostscan module in Cisco AnyConnect Secure Mobility Client 4.0(.00051) and earlier allows local users to write to arbitrary files via crafted IPC messages, aka Bug ID CSCus79173.
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Analysis
by VulDB Data Team • 04/15/2022
The vulnerability identified as CVE-2015-0665 resides within the Hostscan module of Cisco AnyConnect Secure Mobility Client version 4.0.00051 and earlier releases. This flaw represents a critical security weakness that enables local attackers to manipulate the system through crafted inter-process communication messages, potentially leading to arbitrary file write operations. The Hostscan module is designed to perform host health checks and security assessments on client systems, making it a prime target for exploitation due to its privileged execution context and direct system interaction capabilities.
The technical implementation of this vulnerability stems from inadequate input validation within the IPC message handling mechanism of the Hostscan module. When the AnyConnect client processes incoming IPC messages, it fails to properly sanitize or validate the data contained within these messages before using them to determine file paths or write operations. This allows a local malicious user to craft specially formatted IPC messages that contain malicious file paths or data, which the vulnerable module then processes without sufficient security checks. The flaw essentially creates a path traversal or file injection scenario where attacker-controlled data can influence the module's file operations, potentially leading to overwriting critical system files or writing malicious content to arbitrary locations on the filesystem.
The operational impact of this vulnerability extends beyond simple local privilege escalation as it can enable persistent system compromise and broader security breaches. Attackers exploiting this vulnerability could potentially overwrite critical system binaries, modify configuration files, or inject malicious code into the AnyConnect client itself, creating a persistent backdoor. The attack vector is particularly concerning because it requires only local system access, making it difficult to detect and mitigate. This vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, and CWE-73, which covers external control of file name or path, both of which are commonly exploited in file system manipulation attacks. The exploitability of this vulnerability aligns with ATT&CK technique T1059.001 for command and script interpreter, as successful exploitation could enable attackers to execute arbitrary code through modified system files.
Mitigation strategies for CVE-2015-0665 should prioritize immediate patching of affected AnyConnect client versions to the latest available releases that contain the necessary security fixes. Organizations should implement strict access controls and privilege separation to minimize the impact of potential exploitation, ensuring that the AnyConnect client runs with the least necessary privileges. Network segmentation and monitoring should be enhanced to detect unusual IPC message patterns or file system modifications that could indicate exploitation attempts. Additionally, security teams should conduct comprehensive vulnerability assessments to identify any systems running vulnerable versions of the AnyConnect client and establish automated patch management processes. The remediation approach should also include monitoring for suspicious file creation or modification patterns in system directories that could indicate successful exploitation attempts. Regular security audits of client-side security modules and proper input validation mechanisms should be implemented to prevent similar vulnerabilities from emerging in future releases.