CVE-2018-8550 in Windows
Summary
by MITRE
An elevation of privilege exists in Windows COM Aggregate Marshaler, aka "Windows COM Elevation of Privilege Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2019, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
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Analysis
by VulDB Data Team • 06/29/2024
The vulnerability identified as CVE-2018-8550 represents a critical elevation of privilege flaw within the Windows Component Object Model (COM) Aggregate Marshaler component. This weakness allows malicious actors to escalate their privileges from standard user level to SYSTEM level execution within affected Windows operating systems. The vulnerability specifically targets the COM aggregate marshaler functionality that handles object aggregation and method dispatching between different COM objects. The flaw exists in how the system processes certain COM aggregate marshaling operations, creating an opportunity for unauthorized code execution with elevated privileges. Microsoft Windows versions including Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2019, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, and Windows 10 Servers are all affected by this vulnerability.
The technical implementation of this vulnerability stems from improper validation of COM object aggregation within the Windows kernel. When a malicious COM object attempts to aggregate another COM object through the marshaler, the system fails to properly validate the security context and permissions associated with the aggregation operation. This improper validation creates a path where unprivileged users can manipulate COM objects to gain elevated privileges. The flaw manifests when the COM aggregate marshaler processes certain method calls or object references without sufficient security checks, potentially allowing attackers to bypass standard access controls. This vulnerability is particularly dangerous because COM is a fundamental Windows component used extensively throughout the operating system for inter-process communication and object management. The attack vector typically involves crafting malicious COM objects that exploit the aggregate marshaler's failure to validate object relationships and security contexts during the marshaling process.
The operational impact of CVE-2018-8550 is severe and far-reaching within compromised environments. An attacker who successfully exploits this vulnerability can achieve SYSTEM-level privileges, enabling them to perform any action on the affected system including installing malicious software, modifying system files, accessing all user data, and potentially establishing persistent access. The vulnerability can be exploited through various attack scenarios including social engineering campaigns, drive-by downloads, or exploitation of other initial access vectors. Once elevated to SYSTEM level, attackers can leverage this privilege to move laterally across networks, establish backdoors, and conduct advanced persistent threat operations. The vulnerability affects both desktop and server environments, making it particularly dangerous for enterprise networks where servers often run with elevated privileges. Organizations may experience complete system compromise, data breaches, and potential lateral movement to other network segments. The attack surface is broad due to COM's extensive use in Windows applications and system services, making detection and prevention challenging. Security researchers have noted that this vulnerability can be particularly difficult to detect through traditional security monitoring due to its low-level nature within the Windows kernel.
Mitigation strategies for CVE-2018-8550 primarily focus on applying Microsoft's security patches and implementing additional security controls. Organizations should immediately deploy the security update released by Microsoft as part of their regular patch management procedures. The vulnerability is classified under CWE-264, which represents "Permissions, Privileges, and Access Controls" and aligns with ATT&CK technique T1068, "Exploitation for Privilege Escalation." Additional mitigations include implementing Application Control policies such as Windows Defender Application Control or Software Restriction Policies to limit the execution of potentially malicious COM objects. Network segmentation and least privilege principles should be enforced to limit the potential impact of successful exploitation. Security monitoring should include detection of unusual COM object aggregation patterns and privilege escalation attempts. System administrators should also consider disabling unnecessary COM functionality where possible and implementing comprehensive logging of COM-related activities. The vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against kernel-level exploits. Organizations should also conduct regular vulnerability assessments and penetration testing to identify potential exploitation pathways and ensure their security controls remain effective against evolving threats.