CVE-2021-44022 in Apex One
Summary
by MITRE • 12/03/2021
A reachable assertion vulnerability in Trend Micro Apex One could allow an attacker to crash the program on affected installations, leading to a denial-of-service (DoS). Please note: an attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
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Analysis
by VulDB Data Team • 12/09/2021
The vulnerability identified as CVE-2021-44022 represents a reachable assertion failure within Trend Micro Apex One, a comprehensive endpoint protection solution designed to defend against malware and other cyber threats. This specific weakness manifests as an assertion vulnerability that can be triggered through careful manipulation of input data, ultimately leading to program termination and system disruption. The flaw exists within the application's handling of certain data processing operations, where the software fails to properly validate input parameters before proceeding with execution logic. The assertion mechanism, which is typically used during development to verify program correctness and detect unexpected conditions, becomes exploitable in production environments due to insufficient input sanitization.
The technical exploitation of this vulnerability requires an attacker to first gain low-privileged execution capabilities on the target system, as the vulnerability cannot be directly accessed from external network positions. Once an attacker has achieved this initial foothold, they can craft specific inputs that trigger the assertion failure, causing the Apex One service to crash and terminate unexpectedly. This behavior results in a denial-of-service condition that disrupts the endpoint protection capabilities of the affected system. The underlying flaw stems from improper error handling and insufficient validation of user-supplied data within the application's processing pipeline, creating a condition where malformed or specially crafted inputs can force the program into an assertion failure state. This vulnerability falls under the category of software fault injection attacks and can be classified as a CWE-664: Improper Control of a Resource Through Time of Use, where the resource management fails to properly handle edge cases during processing.
The operational impact of CVE-2021-44022 extends beyond simple service disruption, as it compromises the integrity of the security posture on affected endpoints. When the Apex One service crashes, the system loses its real-time protection capabilities, leaving the endpoint vulnerable to malware infections and other cyber threats that the security solution was specifically designed to prevent. This creates a dangerous window where the system is actively protected by no security measures, potentially allowing attackers to escalate privileges or deploy additional malicious payloads. The vulnerability also impacts the availability of security monitoring and logging capabilities, as the crash can interrupt the normal flow of security event processing and reporting. Organizations using Trend Micro Apex One may experience increased security incidents and potential breach opportunities during the period when the service is unavailable due to this assertion failure.
Mitigation strategies for CVE-2021-44022 should prioritize immediate patching of affected systems, as Trend Micro has released updates addressing this specific vulnerability. Organizations should implement network segmentation and access controls to limit potential attack vectors and reduce the likelihood of attackers achieving the initial low-privileged code execution required for exploitation. Security monitoring should be enhanced to detect unusual service termination patterns and potential exploitation attempts, while endpoint detection and response capabilities should be strengthened to identify and block malicious activity that could lead to privilege escalation. System administrators should also consider implementing additional logging and alerting mechanisms to track service stability and quickly identify when the assertion failure has occurred. The vulnerability demonstrates the importance of proper input validation and error handling in security applications, as highlighted by ATT&CK technique T1499.004: Endpoint Denial of Service, which specifically addresses the exploitation of software vulnerabilities to cause service disruption. Organizations should also review their incident response procedures to ensure rapid recovery from service outages and maintain backup security measures during patch deployment windows.