CVE-2020-3350 in AMP for Endpoints
Summary
by MITRE
A vulnerability in the endpoint software of Cisco AMP for Endpoints and Clam AntiVirus could allow an authenticated, local attacker to cause the running software to delete arbitrary files on the system. The vulnerability is due to a race condition that could occur when scanning malicious files. An attacker with local shell access could exploit this vulnerability by executing a script that could trigger the race condition. A successful exploit could allow the attacker to delete arbitrary files on the system that the attacker would not normally have privileges to delete, producing system instability or causing the endpoint software to stop working.
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Analysis
by VulDB Data Team • 10/25/2020
This vulnerability resides in Cisco AMP for Endpoints and Clam AntiVirus software where a race condition flaw exists during file scanning operations. The vulnerability stems from improper synchronization mechanisms that fail to adequately protect critical system resources during concurrent file processing activities. When malicious files are processed through the antivirus scanning pipeline, the race condition can be triggered, allowing an authenticated local user with shell access to manipulate the timing of file operations. The flaw specifically manifests when the endpoint software attempts to handle file deletion operations in parallel with scanning activities, creating a window where unauthorized file removal becomes possible.
The technical exploitation of this vulnerability requires an attacker to have legitimate local shell access to the target system, which represents a privilege escalation scenario rather than a remote attack vector. Attackers can craft specialized scripts that manipulate file system operations to trigger the race condition during scanning processes, effectively bypassing normal file permission controls and access restrictions. This race condition vulnerability directly maps to CWE-367, which describes the weakness of time-of-check to time-of-use flaws where the state of a resource changes between verification and actual use. The timing aspect of this vulnerability makes it particularly challenging to detect and prevent through standard security controls, as the window of opportunity for exploitation is narrow and dependent on specific system states.
The operational impact of this vulnerability extends beyond simple file deletion capabilities to potentially destabilize entire endpoint security infrastructures. When exploited successfully, the vulnerability can cause the endpoint software to become non-responsive or crash entirely, disrupting security monitoring and threat detection capabilities. System instability may occur when critical files required for the antivirus functionality are deleted, potentially creating a cascade effect that compromises the overall security posture of the endpoint. Organizations relying on these security solutions may experience gaps in their threat detection coverage, leaving systems vulnerable to attacks that would normally be prevented by the antivirus software. The vulnerability's potential to cause service disruption makes it particularly dangerous in enterprise environments where endpoint security is critical for maintaining operational continuity.
Mitigation strategies for this vulnerability should focus on immediate software patching and system hardening measures. Cisco has released security advisories containing patches that address the race condition in their AMP for Endpoints software, and organizations should prioritize applying these updates to all affected systems. System administrators should implement additional monitoring controls to detect unusual file deletion patterns or abnormal scanning behavior that might indicate exploitation attempts. Network segmentation and privilege minimization practices can reduce the potential impact of successful exploitation by limiting the scope of files an attacker can target. The vulnerability's characteristics align with ATT&CK technique T1070.004, which covers the use of file deletion to evade detection, making it essential for organizations to implement comprehensive file integrity monitoring solutions. Regular security assessments should include verification of endpoint software configurations to ensure that race condition vulnerabilities are properly addressed through proper synchronization mechanisms and access controls.