CVE-2025-55693 in Windows
Summary
by MITRE • 10/14/2025
Use after free in Windows Kernel allows an unauthorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 11/22/2025
This vulnerability represents a critical use-after-free condition within the Windows kernel that enables local privilege escalation attacks. The flaw occurs when kernel-mode components fail to properly validate memory management operations, creating opportunities for malicious code to exploit freed memory regions. Such vulnerabilities are particularly dangerous because they operate at the kernel level where the highest system privileges reside, allowing attackers to bypass standard security boundaries. The issue stems from improper handling of reference counting or object lifecycle management within kernel data structures, which can lead to memory corruption when objects are accessed after being deallocated.
The technical implementation of this vulnerability involves memory management routines that do not adequately enforce object validity checks before allowing access to kernel memory regions. When a kernel object is freed but references to it persist, attackers can manipulate the memory layout to redirect execution flow or inject malicious code into privileged contexts. This particular flaw demonstrates characteristics consistent with CWE-416 Use After Free, which specifically addresses the condition where a pointer is used after the memory it points to has been freed. The vulnerability's exploitation requires local system access, meaning an attacker must first establish a foothold on the target system before attempting privilege escalation.
From an operational impact perspective, this vulnerability creates significant risk for organizations relying on Windows systems, particularly in environments where local user accounts exist or where system administrators might inadvertently execute malicious code. The local privilege escalation capability allows attackers to gain SYSTEM-level privileges, enabling complete system compromise without requiring network-based attack vectors. This makes the vulnerability particularly attractive to threat actors who may have already achieved initial access through other means such as phishing or remote exploitation of other vulnerabilities. The attack surface extends beyond simple local execution as the compromised system can then be used as a pivot point for lateral movement within network environments.
Mitigation strategies for this vulnerability should focus on immediate patch deployment from Microsoft, which typically involves applying the relevant security updates that address the specific kernel memory management flaw. Organizations should also implement additional security controls such as enabling kernel-mode driver validation, restricting local user privileges, and monitoring for anomalous kernel memory access patterns. The ATT&CK framework categorizes this type of vulnerability under T1068, which covers Exploitation for Privilege Escalation, and T1543, which addresses Create or Modify System Process. Network segmentation and principle of least privilege enforcement can help reduce the impact if exploitation occurs, while endpoint detection and response solutions should be configured to monitor for suspicious kernel-mode activities that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should include checks for similar memory corruption vulnerabilities to prevent similar issues from remaining undetected.