CVE-2018-8412 in Office
Summary
by MITRE
An elevation of privilege vulnerability exists when the Microsoft AutoUpdate (MAU) application for Mac improperly validates updates before executing them, aka "Microsoft (MAU) Office Elevation of Privilege Vulnerability." This affects Microsoft Office.
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Analysis
by VulDB Data Team • 05/02/2023
The vulnerability identified as CVE-2018-8412 represents a critical elevation of privilege flaw within Microsoft AutoUpdate (MAU) for macOS systems. This weakness allows attackers to escalate their privileges by exploiting improper validation mechanisms during the update process. The vulnerability specifically impacts Microsoft Office applications running on macOS platforms, making it particularly concerning for enterprise environments where Office productivity suites are widely deployed. The flaw resides in how MAU handles update validation, creating an opportunity for malicious actors to execute arbitrary code with elevated privileges.
The technical nature of this vulnerability stems from insufficient input validation within the MAU application's update processing pipeline. When MAU receives update packages, it fails to properly verify the integrity and authenticity of these updates before execution. This validation gap enables attackers to craft malicious update payloads that bypass normal security checks. The vulnerability operates at the privilege level where the update process executes, allowing successful exploitation to result in elevated system privileges rather than remaining confined to the user context. This type of flaw typically falls under CWE-20, which encompasses improper input validation, and specifically relates to CWE-787, representing out-of-bounds write conditions that can occur when validation fails.
The operational impact of CVE-2018-8412 extends beyond individual system compromise to potentially affect entire organizational networks. Attackers who successfully exploit this vulnerability can gain administrative privileges on affected Mac systems, enabling them to install persistent backdoors, exfiltrate sensitive data, or deploy additional malware. The attack vector typically involves delivering a malicious update package that appears legitimate to the MAU application, making detection challenging for security teams. This vulnerability is particularly dangerous in enterprise environments where Microsoft Office is extensively used, as it can serve as a foothold for broader network infiltration. The flaw's impact aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' and demonstrates how attackers can leverage software vulnerabilities to gain elevated system access.
Microsoft addressed this vulnerability through patch updates that strengthened the validation mechanisms within MAU. Organizations should prioritize immediate deployment of these security patches to mitigate the risk of exploitation. System administrators should also implement additional security measures such as monitoring for unusual update activity and verifying the integrity of update packages before installation. The vulnerability serves as a reminder of the critical importance of proper update validation in software distribution systems, particularly for applications that execute with elevated privileges. Security professionals should consider implementing network segmentation and access controls to limit the potential impact if exploitation occurs, while also maintaining regular vulnerability assessments to identify similar weaknesses in other update mechanisms.