CVE-2018-8244 in Outlook
Summary
by MITRE
An elevation of privilege vulnerability exists when Microsoft Outlook does not validate attachment headers properly, aka "Microsoft Outlook Elevation of Privilege Vulnerability." This affects Microsoft Office, Microsoft Outlook.
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Analysis
by VulDB Data Team • 03/27/2023
The vulnerability identified as CVE-2018-8244 represents a critical elevation of privilege flaw within Microsoft Outlook that stems from improper validation of attachment headers. This weakness allows malicious actors to potentially execute arbitrary code with elevated privileges, effectively bypassing standard security controls that protect against unauthorized system access. The vulnerability specifically impacts Microsoft Office and Microsoft Outlook products, making it a significant concern for enterprise environments where these applications are widely deployed. The flaw exists in the way Outlook processes email attachments, particularly when handling certain header information that should be rigorously validated before execution.
From a technical perspective, the vulnerability occurs when Outlook fails to properly sanitize or validate attachment headers during the parsing process. This improper validation creates a pathway for attackers to craft specially crafted email messages that contain malicious attachment headers designed to exploit the validation gap. The vulnerability is classified under CWE-20, which represents "Improper Input Validation," a fundamental weakness that allows attackers to inject malicious data into applications. When Outlook processes these malformed headers, it may inadvertently execute code or manipulate system resources in ways that were not intended by the application's design. The flaw essentially allows an attacker to escalate privileges from a standard user account to a higher-privileged level, potentially gaining access to sensitive system resources or data.
The operational impact of CVE-2018-8244 extends beyond simple privilege escalation, as it creates opportunities for broader security compromise within affected environments. Attackers could leverage this vulnerability to install malware, modify system configurations, or access confidential information stored on affected systems. The vulnerability is particularly dangerous in enterprise settings where Outlook is commonly used for business communications and where users may not be sufficiently security-aware to recognize suspicious email attachments. Organizations that have not implemented proper patch management protocols may find themselves vulnerable to attacks exploiting this weakness. The attack surface is further expanded when considering that Outlook is frequently used in conjunction with other Microsoft Office applications, creating potential chain reactions that could compromise additional system components.
Mitigation strategies for this vulnerability primarily focus on timely patch deployment and enhanced email security measures. Microsoft released security updates that address the improper validation of attachment headers in affected Outlook versions, and organizations should prioritize immediate implementation of these patches. System administrators should also implement additional email filtering measures that can identify and block potentially malicious attachments before they reach end users. The vulnerability aligns with ATT&CK technique T1059, which covers "Command and Scripting Interpreter," as attackers may use the elevated privileges to execute commands or scripts on compromised systems. Organizations should also consider implementing principle of least privilege controls to limit the damage that could occur even if an attacker successfully exploits this vulnerability. Network segmentation and email security appliances can provide additional layers of protection against attacks targeting this specific weakness.