CVE-2018-10959 in Defendpoint
Summary
by MITRE
Avecto Defendpoint 4 prior to 4.4 SR6 and 5 prior to 5.1 SR1 has an Untrusted Search Path vulnerability, exploitable by modifying environment variables to trigger automatic elevation of an attacker's process launch.
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Analysis
by VulDB Data Team • 08/29/2023
The vulnerability identified as CVE-2018-10959 affects Avecto Defendpoint versions prior to 4.4 SR6 and 5.1 SR1, representing a critical untrusted search path weakness that fundamentally undermines the security posture of endpoint protection systems. This flaw exists within the software's process execution mechanism where the application fails to properly validate or sanitize environment variables during process initialization, creating a pathway for malicious actors to manipulate the execution flow through environment variable modification.
The technical implementation of this vulnerability stems from improper handling of dynamic link library (dll) loading sequences within the Defendpoint application framework. When processes are launched, the software relies on predictable search paths that include directories specified through environment variables such as PATH or other system variables. Attackers can exploit this by injecting malicious dlls into these search paths, causing the system to execute unauthorized code with elevated privileges. This represents a classic privilege escalation vector that aligns with CWE-426 Untrusted Search Path vulnerability classification, where the system fails to properly validate the integrity of executable components.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally compromises the integrity of the endpoint protection system itself. An attacker who successfully exploits this vulnerability can elevate their process privileges to system level, effectively bypassing the very security controls that Defendpoint is designed to enforce. This creates a dangerous scenario where malicious actors can execute arbitrary code with the highest system privileges while remaining undetected by the protection mechanisms that should be monitoring and preventing such activities. The exploitation directly violates the principle of least privilege and undermines the core security model of endpoint protection solutions.
From a threat actor perspective, this vulnerability provides a straightforward path to persistent system compromise with minimal detection risk. The attack vector requires only the ability to modify environment variables, which can be achieved through various initial compromise techniques including social engineering, phishing, or exploitation of other vulnerabilities in the system. The vulnerability's exploitability is further enhanced by the fact that it operates at the system level, making it particularly dangerous for enterprise environments where endpoint protection systems are expected to provide comprehensive security coverage. Security professionals should note that this vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', and represents a critical gap in the security architecture that requires immediate remediation.
Mitigation strategies for CVE-2018-10959 should focus on both immediate patching and architectural improvements to prevent similar vulnerabilities in the future. Organizations must prioritize updating to Avecto Defendpoint versions 4.4 SR6 or 5.1 SR1, which contain the necessary fixes to address the untrusted search path issue. Additionally, system administrators should implement strict environment variable controls and monitor for unauthorized modifications to critical system paths. The solution architecture should incorporate proper input validation and sanitization of environment variables, ensuring that only trusted paths are included in the search sequence. Security teams should also consider implementing process monitoring and anomaly detection to identify suspicious dll loading patterns that could indicate exploitation attempts. This vulnerability serves as a reminder of the critical importance of secure coding practices and proper validation of system components, particularly in security-critical applications where the failure of one component can undermine the entire security framework.