{"id":85865,"date":"2025-11-17T15:30:20","date_gmt":"2025-11-17T15:30:20","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T00:00:00","slug":"cve-2025-29833-time-of-check-time-of-use-toctou-race-condition-in-windows-virtual-machine-bus","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-29833-time-of-check-time-of-use-toctou-race-condition-in-windows-virtual-machine-bus\/","title":{"rendered":"CVE-2025-29833: Time-of-check Time-of-use (TOCTOU) Race Condition in Windows Virtual Machine Bus<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

The vulnerability CVE-2025-29833 is a critical security flaw in the Windows Virtual Machine Bus that allows an unauthorized attacker to exploit a time-of-check time-of-use (TOCTOU) race condition. This vulnerability affects all systems that use the Windows Virtual Machine Bus. Given the widespread use of Windows systems across organizations globally, this vulnerability could potentially lead to significant security breaches if left unaddressed.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-29833
\nSeverity: High (7.7 CVSS Score)
\nAttack Vector: Local
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Potential system compromise or data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Windows Virtual Machine Bus | All versions prior to patch<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The vulnerability exploits a time-of-check time-of-use (TOCTOU) race condition in the Windows Virtual Machine Bus. In a TOCTOU race condition, an attacker could potentially alter the state of the system between the time it is checked and the time it is used for some operation. In this case, this window of opportunity could allow an unauthorized attacker to execute arbitrary code locally, potentially leading to system compromise or data leakage.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

The following is a conceptual example of how this vulnerability might be exploited:<\/p>\n

# Assuming an attacker has local access to the virtual machine\n# Time-of-check\nif (Check_VM_Bus_State() == SAFE) {\n# Time-of-use\n# In between these two operations, an attacker alters the state\nExecute_Code_In_VM_Bus(\"malicious_code.exe\");\n}<\/code><\/pre>\n
In this conceptual example, the attacker takes advantage of the time window between the check and the use of the Virtual Machine Bus to execute a malicious code.
\nPlease note that this is a simplified representation and actual exploitation would be more complex and require in-depth knowledge of the system’s architecture and the Windows Virtual Machine Bus.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview The vulnerability CVE-2025-29833 is a critical security flaw in the Windows Virtual Machine Bus that allows an unauthorized attacker to exploit a time-of-check time-of-use (TOCTOU) race condition. This vulnerability affects all systems that use the Windows Virtual Machine Bus. Given the widespread use of Windows systems across organizations globally, this vulnerability could potentially lead […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-85865","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t