Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows MIDI Service Module allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.0",
  "pubDate": "2026-08-11T17:18:18.870Z",
  "pubdate": "2026-08-11T17:18:18.870Z",
  "executiveSummary": "A privilege escalation vulnerability stemming from a concurrent execution using shared resource with improper synchronization, commonly known as a race condition, exists within the Windows MIDI Service Module.\nThis security flaw enables an authorized local attacker to execute arbitrary operations or manipulate shared states to elevate privileges on the affected host.\nThe impacted product is the Windows MIDI Service Module, which fails to properly synchronize access to critical shared resources.\nThe risk implications are significant, as successful exploitation bridges standard user privileges to higher integrity levels, potentially compromising the underlying operating system security boundary.\nAttacker capabilities require local access to the target machine alongside prior authorization or execution rights.\nSpecific prerequisites include the ability to interact directly with the vulnerable Windows MIDI Service Module to win the race condition window during concurrent execution requests.",
  "technicalDetails": "The root cause of the vulnerability resides in the Windows MIDI Service Module's handling of concurrent execution flows accessing shared resources without proper synchronization mechanisms such as mutexes, critical sections, or appropriate locking primitives.\nThis improper synchronization introduces a classic race condition vulnerability where multiple threads or processes can manipulate the same underlying memory or system resource simultaneously.\nThe vulnerable component is identified as the Windows MIDI Service Module.\nAuthentication requirements dictate that the attacker must already possess local access to the system, while privilege requirements indicate that a standard user can initiate the local escalation sequence.\nNetwork exposure is non-existent as this vector requires local system interaction.\nThe exploitation method relies on the attacker spawning concurrent threads or processes designed to interleave operations precisely between the check and use states of the shared resource managed by the Windows MIDI Service Module.\nThe step-by-step attack flow begins with the attacker establishing a local session and preparing a payload or harness that continuously interacts with the MIDI service APIs.\nBy bombarding the service with overlapping requests, the attacker induces a timing window where the shared resource is accessed inconsistently.\nWhen the race condition is successfully triggered, the service processes invalid or maliciously modified states, leading to unintended memory corruption, logic flaws, or unsafe object manipulation.\nThe payload behavior leverages this unstable state to subvert standard access control checks enforced by the operating system.\nThe post-exploitation impact culminates in local privilege escalation, allowing the attacker to execute code or manipulate system configurations at an elevated integrity level granted by the service context."
}