CVE-2024-30088

What is the Windows Kernel Object Manager?

The Windows Kernel Object Manager is the subsystem responsible for managing named objects — files, registry keys, mutexes, events, and other kernel objects — and enforcing access control decisions on them. Virtually every operation in Windows (file I/O, process creation, inter-process communication) flows through the Object Manager. Its internal state management involves checking access rights against object properties and then performing operations on those objects; a time-of-check-to-time-of-use (TOCTOU) race condition between the check and the use opens a window where the security decision becomes invalid before it is enforced.

Overview

CVE-2024-30088 is a TOCTOU race condition vulnerability in the Windows Kernel that allows a local attacker with low privileges to escalate to SYSTEM. Microsoft patched it in June 2024 Patch Tuesday; CISA added it to the KEV catalog in October 2024 — four months later — with confirmed ransomware use, indicating threat actors were actively exploiting unpatched systems as a privilege escalation step in ransomware deployment chains.

Affected Versions

Technical Details

CWE-367 (TOCTOU Race Condition). The vulnerability involves a race between a security check and the subsequent use of the checked resource in a kernel code path. The kernel checks whether a calling process has sufficient privileges to perform an operation, then between that check and the actual operation, another thread can modify the object's state or replace the object reference. The operation then executes against the modified object using the already-granted privilege decision, bypassing the security check.

The High Attack Complexity (AC:H) reflects the race condition requirement — exploiting a TOCTOU bug requires winning a timing window between two kernel operations, which requires repeated attempts or thread timing techniques. However, dedicated exploit code using techniques such as thread spraying, CPU affinity manipulation, or NtAlertResumeThread timing can make the race reliably winnable in practice. Once the race is won, the result is an escalation of the attacker's process token to SYSTEM.

Discovery

Patched as part of the June 2024 Patch Tuesday cycle. The four-month delay between the patch and CISA KEV addition, combined with confirmed ransomware use, suggests that ransomware groups or their affiliates reverse-engineered the June Patch Tuesday diff and developed working exploits that were then deployed against unpatched enterprise targets.

Exploitation Context

Windows kernel LPE vulnerabilities patched in Patch Tuesday often have working exploits appear in the wild within weeks as attackers reverse-engineer the patch to understand the root cause and develop exploits. CVE-2024-30088 fits this pattern: patched in June, exploited in the wild by October. Ransomware operators use kernel LPE bugs to escalate from initial access (often a low-privilege phishing foothold) to SYSTEM before deploying their encryptor — SYSTEM privileges are needed to stop security services, delete shadow copies, and encrypt protected files.

Remediation

1. Apply the June 2024 Windows security updates (Patch Tuesday, June 11, 2024) to all affected systems.
2. Prioritize patching systems that have not received updates since May 2024 — systems in that state have been exposed to exploitation for months.
3. Enable virtualization-based security (VBS) and Hypervisor-Protected Code Integrity (HVCI) on supported hardware to increase the difficulty of kernel exploitation.
4. Monitor for indicators of ransomware pre-deployment activity: shadow copy deletion, bulk service termination, and unusual SYSTEM-level process creation from low-privilege parent processes.