CVE-2026-79808 in ClearPass Policy Manager
Summary
by MITRE • 10/06/2026
A buffer overflow vulnerability exists in the OnGuard agent of ClearPass Policy Manager. Successful exploitation could allow an authenticated local user to execute arbitrary code with elevated privileges on the affected host or to disrupt the availability of the affected service.
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Analysis
by VulDB Data Team • 10/07/2026
The identified security flaw resides within the OnGuard agent component of Aruba ClearPass Policy Manager, a critical infrastructure tool used for network access control and policy enforcement. This vulnerability is classified as a buffer overflow, specifically involving improper handling of input data that exceeds the allocated memory boundaries. The technical nature of this defect suggests that the application fails to adequately validate or sanitize user-supplied information before copying it into fixed-size buffers in memory. When an attacker provides input larger than what the buffer can accommodate, the excess data overwrites adjacent memory locations. This corruption can alter program execution flow by modifying return addresses on the stack or function pointers, thereby allowing the injection and execution of arbitrary machine code. Given that this vulnerability affects a local agent running with elevated privileges, the potential for privilege escalation is significant, as successful exploitation grants the attacker control over processes operating under system-level permissions rather than standard user rights.
The operational impact of exploiting this buffer overflow extends beyond simple remote code execution or service disruption. Because the OnGuard agent typically runs on endpoints to enforce security policies and monitor compliance, compromising it allows an authenticated local user to bypass network access controls entirely. An attacker could manipulate policy decisions, disable monitoring capabilities, or install persistent backdoors that evade standard detection mechanisms due to their integration with legitimate system processes. Furthermore, if exploitation is achieved through denial-of-service vectors rather than code execution, the availability of critical security services on affected hosts would be compromised. This disruption can lead to a state where endpoints are no longer monitored for compliance, potentially allowing non-compliant or malicious devices to connect to the network without restriction. The combination of local authentication requirements and elevated privilege levels makes this vulnerability particularly dangerous in environments where insider threats or physical access to workstations is possible.
From a classification perspective, this issue aligns with CWE-120, Buffer Copy without Checking Size of Input, which describes the fundamental error of copying data into a buffer without verifying that it fits within the allocated space. Additionally, the exploitation path relates to CWE-78, Improper Neutralization of Special Elements used in an OS Command, if the overflow leads to command injection scenarios common in such agents. In terms of adversary tactics, this vulnerability supports ATT&CK technique T1059, Command and Scripting Interpreter, as well as T1068, Exploitation for Privilege Escalation. Attackers leveraging this flaw would likely follow a kill chain that begins with local access acquisition, proceeds through privilege escalation via the buffer overflow, and culminates in lateral movement or persistence within the network infrastructure managed by ClearPass Policy Manager.
Mitigation strategies must address both immediate remediation and long-term architectural resilience. The primary defense is to apply vendor-provided patches immediately upon release, as these updates typically include bounds checking logic and input validation routines that prevent the buffer overflow condition from occurring. Organizations should also enforce strict least-privilege principles for local user accounts on systems running the OnGuard agent, ensuring that even if an attacker gains access, their ability to exploit elevated privileges is limited by additional security controls such as application whitelisting or data execution prevention (DEP) and address space layout randomization (ASLR). Network segmentation should be utilized to isolate ClearPass Policy Manager components from general user networks, reducing the attack surface. Regular vulnerability scanning focused on endpoint agents and continuous monitoring for anomalous process behavior can help detect exploitation attempts early. Finally, maintaining up-to-date antivirus definitions and endpoint detection and response tools is essential for identifying post-exploitation activities that may result from successful buffer overflow attacks.