CVE-2020-0626 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists in the way that the Windows Search Indexer handles objects in memory, aka 'Windows Search Indexer Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-0613, CVE-2020-0614, CVE-2020-0623, CVE-2020-0625, CVE-2020-0627, CVE-2020-0628, CVE-2020-0629, CVE-2020-0630, CVE-2020-0631, CVE-2020-0632, CVE-2020-0633.
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Analysis
by VulDB Data Team • 03/21/2024
The vulnerability described in CVE-2020-0626 represents a critical elevation of privilege flaw within the Windows Search Indexer component, specifically concerning how it processes objects in memory. This issue affects Microsoft Windows operating systems and allows a malicious actor with low-privilege user access to escalate their privileges to system-level access. The vulnerability stems from improper memory handling mechanisms within the search indexing service, which is designed to catalog and index files and content across the system for efficient search operations. The Windows Search Indexer is a background service that continuously monitors and indexes content, making it a prime target for exploitation due to its persistent nature and elevated system access requirements.
The technical root cause of this vulnerability lies in the manner in which the Windows Search Indexer manages memory objects during the indexing process. When processing certain file types or content structures, the indexer fails to properly validate or sanitize memory allocations, creating opportunities for memory corruption that can be exploited by attackers. This flaw specifically manifests when the indexer encounters malformed or specially crafted objects that trigger buffer overflows or other memory manipulation conditions. The vulnerability is categorized under CWE-121, which addresses stack-based buffer overflow conditions, and aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation'. The memory handling error occurs during the processing of indexed content, particularly when dealing with complex file structures or embedded objects that the indexer attempts to parse and catalog.
The operational impact of CVE-2020-0626 extends beyond simple privilege escalation, as it provides attackers with the ability to gain complete system control without requiring physical access or sophisticated attack vectors. Once successfully exploited, the vulnerability allows threat actors to execute arbitrary code with system-level privileges, potentially leading to full system compromise, data exfiltration, or persistent backdoor installation. The attack surface is significant since the Windows Search Indexer runs continuously in the background and has broad access to system resources and file structures. This makes the vulnerability particularly dangerous in enterprise environments where search indexing is enabled across multiple systems and file shares. The vulnerability is especially concerning because it can be triggered through normal user activities, such as opening or processing files that contain maliciously crafted content, making it difficult to detect and prevent through traditional security measures.
Mitigation strategies for CVE-2020-0626 should focus on both immediate patching and operational security improvements. Microsoft released security updates in April 2020 that address this vulnerability through memory validation improvements in the Windows Search Indexer component. Organizations should prioritize applying these patches immediately to all affected systems, particularly those running Windows 10, Windows Server 2016, and Windows Server 2019. Additional protective measures include implementing least privilege access controls, disabling unnecessary search indexing services where possible, and monitoring for unusual indexing activity that might indicate exploitation attempts. Network segmentation and endpoint detection and response solutions can help identify potential exploitation attempts by monitoring for suspicious privilege escalation activities. The vulnerability also highlights the importance of maintaining up-to-date security hygiene practices, including regular system updates, security configuration reviews, and continuous monitoring of system logs for signs of privilege escalation or unusual system behavior. Organizations should also consider implementing application whitelisting policies to restrict execution of potentially malicious files that could trigger the vulnerability during indexing operations.