CVE-2016-0137 in Office
Summary
by MITRE
The Click-to-Run (C2R) implementation in Microsoft Office 2013 SP1 and 2016 allows local users to bypass the ASLR protection mechanism via a crafted application, aka "Microsoft APP-V ASLR Bypass."
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/16/2022
The vulnerability identified as CVE-2016-0137 represents a critical security flaw in Microsoft Office's Click-to-Run implementation affecting versions 2013 SP1 and 2016. This issue specifically targets the Address Space Layout Randomization protection mechanism, which is a fundamental security feature designed to prevent exploitation of memory corruption vulnerabilities by randomizing the memory layout of processes. The vulnerability manifests through a crafted application that can effectively bypass ASLR protections, thereby undermining the security posture of systems running affected Office versions.
The technical flaw resides in how the Click-to-Run service handles application virtualization and memory management during the execution of Office applications. When a malicious application attempts to exploit this vulnerability, it can manipulate the memory layout to predict or determine the locations of critical system components that would normally be randomized by ASLR. This bypass allows attackers to execute code more reliably by overcoming one of the primary defenses against exploitation techniques such as return-oriented programming and other advanced attack vectors that depend on knowing memory addresses. The vulnerability operates at the application virtualization layer where Microsoft APP-V (Application Virtualization) components interact with the Office Click-to-Run service, creating a pathway for privilege escalation and code execution.
The operational impact of this vulnerability extends beyond simple local privilege escalation as it provides attackers with a foothold that can be leveraged for more sophisticated attacks. Systems running affected Office versions become susceptible to exploitation through various attack vectors including malicious documents, phishing campaigns, or drive-by downloads that could trigger the vulnerable Click-to-Run service. The bypass of ASLR protection means that attackers no longer need to rely on information leaks or other complex techniques to determine memory layouts, significantly reducing the difficulty of exploitation. This vulnerability particularly affects enterprise environments where Office applications are widely deployed and where attackers may be attempting to establish persistent access or escalate privileges within the network.
Organizations should implement immediate mitigations including applying the relevant Microsoft security updates and patches released in response to this vulnerability. The recommended approach involves updating to the latest versions of Microsoft Office that contain fixes for the Click-to-Run implementation and ASLR bypass mechanisms. Security teams should also consider implementing additional controls such as application whitelisting policies, enhanced monitoring of Click-to-Run service activity, and regular security assessments of Office deployment configurations. Network segmentation and user access controls can help limit the potential impact of exploitation attempts. From a compliance perspective, this vulnerability aligns with CWE-119 (Improper Access Control) and CWE-125 (Out-of-bounds Read) categories, and maps to ATT&CK techniques involving privilege escalation and execution through legitimate system processes. The vulnerability demonstrates the importance of maintaining up-to-date security patches and proper application virtualization configurations in enterprise security defenses.