CVE-2019-3972 in Comodo
Summary
by MITRE
Comodo Antivirus versions 12.0.0.6810 and below are vulnerable to Denial of Service affecting CmdAgent.exe via an unprotected section object "<GUID>_CisSharedMemBuff". This section object is exposed by CmdAgent and contains a SharedMemoryDictionary object, which allows a low privileged process to modify the object data causing CmdAgent.exe to crash.
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Analysis
by VulDB Data Team • 11/01/2023
The vulnerability identified as CVE-2019-3972 affects Comodo Antivirus versions 12.0.0.6810 and earlier, presenting a significant denial of service risk through improper access control mechanisms. This flaw specifically targets the CmdAgent.exe process which serves as a critical component in the antivirus infrastructure. The vulnerability stems from an unprotected shared memory section object that exposes sensitive internal data structures to unauthorized processes. The vulnerable section object is identified by the specific naming convention "<GUID>_CisSharedMemBuff" which serves as an entry point for exploitation attempts.
The technical implementation of this vulnerability involves a SharedMemoryDictionary object that is improperly exposed through the unprotected section. This shared memory mechanism allows processes with minimal privileges to manipulate internal data structures that should remain protected within the security boundaries of the antivirus application. The flaw represents a classic case of inadequate access control where privileged resources are accessible to unprivileged users through improper object exposure. When a low privileged process attempts to modify the shared memory dictionary object, it triggers an invalid memory access condition that leads to the CmdAgent.exe process termination.
The operational impact of this vulnerability extends beyond simple service disruption as it compromises the core functionality of the antivirus solution. CmdAgent.exe represents a fundamental component responsible for various security operations including process monitoring, system integrity checks, and communication with the antivirus engine. When this process crashes due to shared memory corruption, it creates a cascading effect that can render the antivirus protection ineffective. The vulnerability is particularly concerning because it requires no elevated privileges to exploit, making it accessible to any user on the system regardless of their security context. This characteristic aligns with attack patterns documented in the attack tree framework where adversaries seek to compromise security services through low-effort, high-impact methods.
From a cybersecurity perspective, this vulnerability demonstrates poor adherence to secure coding practices and memory management principles. The exposure of internal shared memory objects without proper access control mechanisms violates fundamental security concepts outlined in the CWE (Common Weakness Enumeration) catalog, specifically categorizing under weaknesses related to improper access control and improper handling of shared resources. The vulnerability also maps to ATT&CK technique T1486 which involves data manipulation and system resource exhaustion through service disruption. Organizations utilizing affected Comodo Antivirus versions face potential exposure to persistent threats that could exploit this vulnerability to gain continued access to compromised systems while disrupting security monitoring capabilities.
The mitigation strategy for this vulnerability requires immediate patch deployment from Comodo to address the access control flaw in CmdAgent.exe. System administrators should prioritize updating to Comodo Antivirus versions that contain fixed implementations of the shared memory handling mechanisms. Additionally, implementing process monitoring and anomaly detection for CmdAgent.exe behavior can help identify exploitation attempts. Network segmentation and privilege separation measures should be reinforced to limit potential impact if exploitation occurs. The vulnerability highlights the importance of regular security assessments and proper access control implementation in security applications, particularly those that operate with elevated privileges and manage critical system resources.