CVE-2018-8311 in Lync
Summary
by MITRE
A remote code execution vulnerability exists when Skype for Business and Microsoft Lync clients fail to properly sanitize specially crafted content, aka "Remote Code Execution Vulnerability in Skype For Business and Lync." This affects Skype, Microsoft Lync.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 04/05/2023
The vulnerability identified as CVE-2018-8311 represents a critical remote code execution flaw affecting Skype for Business and Microsoft Lync client applications. This security weakness stems from insufficient input validation and content sanitization mechanisms within the affected software platforms. The vulnerability specifically manifests when these applications process specially crafted content that contains malicious payloads designed to exploit the improper handling of user-supplied data. The flaw enables attackers to execute arbitrary code on target systems with the privileges of the authenticated user, potentially leading to complete system compromise and lateral movement within network environments. Microsoft classified this issue as a remote code execution vulnerability due to the ability of attackers to remotely deliver malicious content that triggers the exploitable condition without requiring local system access.
The technical root cause of CVE-2018-8311 aligns with CWE-79, which describes cross-site scripting vulnerabilities resulting from insufficient input validation and sanitization. The vulnerability occurs within the client-side processing logic where Skype for Business and Lync applications fail to adequately sanitize user-provided content before rendering it within the application interface. Attackers can craft malicious content that includes embedded scripts or executable code sequences that bypass the normal security boundaries of the client applications. This improper sanitization allows the malicious content to be interpreted and executed as legitimate application functionality, creating a pathway for remote code execution. The vulnerability affects both desktop and mobile client implementations, making it particularly dangerous as it can be exploited through various communication channels including instant messaging, voice calls, and video conferences.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass significant enterprise security risks. Organizations utilizing Skype for Business and Lync services face potential data breaches, system compromise, and unauthorized access to sensitive corporate communications. The vulnerability can be exploited through various attack vectors including malicious instant messages, voice messages, or video conference invitations that contain crafted payloads. Once successfully exploited, attackers can establish persistent access to compromised systems, escalate privileges, and potentially move laterally within the network infrastructure. The attack surface is particularly wide given that these applications are commonly used for business communications and often have elevated privileges within corporate environments. Security teams must consider the potential for widespread impact across multiple endpoints and the difficulty of detecting such attacks, as they may appear as legitimate user communications.
Mitigation strategies for CVE-2018-8311 should prioritize immediate patch deployment from Microsoft as the primary defense mechanism. Organizations should implement network segmentation and access controls to limit the potential impact of successful exploitation attempts. Security monitoring should focus on unusual communication patterns, unexpected code execution attempts, and anomalous network traffic originating from affected client systems. The implementation of email and instant messaging content filtering solutions can provide additional layers of protection by identifying and blocking malicious content before it reaches end users. Organizations should also consider disabling unnecessary features and functionality within the affected applications to reduce the attack surface. According to ATT&CK framework, this vulnerability maps to T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) techniques, emphasizing the need for comprehensive endpoint protection and behavioral monitoring. Regular security assessments and user awareness training should complement technical controls to prevent successful exploitation through social engineering or phishing attacks that may leverage this vulnerability.