CVE-2016-4025 in Avast!
Summary
by MITRE
Avast Internet Security v11.x.x, Pro Antivirus v11.x.x, Premier v11.x.x, Free Antivirus v11.x.x, Business Security v11.x.x, Endpoint Protection v8.x.x, Endpoint Protection Plus v8.x.x, Endpoint Protection Suite v8.x.x, Endpoint Protection Suite Plus v8.x.x, File Server Security v8.x.x, and Email Server Security v8.x.x allow attackers to bypass the DeepScreen feature via a DeviceIoControl call.
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Analysis
by VulDB Data Team • 07/26/2022
The vulnerability identified as CVE-2016-4025 represents a critical security flaw in multiple Avast security products spanning various product lines including Internet Security, Pro Antivirus, Premier, Free Antivirus, Business Security, and several endpoint protection suites. This vulnerability specifically affects versions 11.x.x for the main security products and 8.x.x for the endpoint and server variants, creating a widespread impact across Avast's security portfolio. The flaw allows malicious actors to circumvent the DeepScreen feature, which is designed to provide advanced threat detection and analysis capabilities within the security ecosystem.
The technical implementation of this vulnerability stems from improper handling of DeviceIoControl calls within the affected Avast products. DeviceIoControl is a Windows API function used for communication with device drivers, and when improperly implemented, it can create attack vectors that allow unauthorized access to system resources. In this case, the vulnerability enables attackers to send crafted DeviceIoControl requests that bypass the intended security checks and DeepScreen analysis mechanisms. This flaw falls under the CWE-119 category of "Improper Access Control" and specifically relates to inadequate input validation and privilege escalation opportunities within the kernel-level driver components.
The operational impact of this vulnerability is severe as it allows attackers to bypass critical threat detection capabilities that are essential for protecting systems from advanced malware and zero-day exploits. When the DeepScreen feature is bypassed, attackers can execute malicious code without triggering the comprehensive analysis that would normally occur, effectively rendering the advanced threat protection mechanisms ineffective. This creates a significant risk for enterprise environments where these products are deployed, as it allows threat actors to perform malicious activities while remaining undetected by the security software that is supposed to protect against such threats. The vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter and T1070.004 for Indicator Removal on Host, as it enables both execution of malicious code and evasion of security controls.
Organizations using affected Avast products should immediately implement mitigations including applying the latest security patches released by Avast, implementing network segmentation to limit attack surface, and monitoring for suspicious DeviceIoControl activity patterns. Security teams should also consider disabling or restricting the affected DeepScreen feature until proper patches are deployed, and conduct thorough security assessments to identify any potential compromise within their environments. The vulnerability demonstrates the critical importance of proper input validation and access control implementation in security software, as flaws in these fundamental areas can undermine the entire security posture of affected systems.