CVE-2025-49690 Overview
CVE-2025-49690 is a race condition vulnerability in the Windows Capability Access Management Service (camsvc). The flaw arises from concurrent execution using a shared resource with improper synchronization [CWE-362]. An authenticated local attacker can exploit the race window to elevate privileges on affected Windows desktop and server systems. Microsoft addressed the issue in its July 2025 security update cycle.
Critical Impact
Successful exploitation grants an unauthorized local attacker elevated privileges, compromising confidentiality, integrity, and availability across the affected host.
Affected Products
- Microsoft Windows 10 (1809, 21H2, 22H2)
- Microsoft Windows 11 (22H2, 23H2, 24H2)
- Microsoft Windows Server 2019, 2022, 2022 23H2, and 2025
Discovery Timeline
- 2025-07-08 - CVE-2025-49690 published to NVD
- 2025-07-15 - Last updated in NVD database
Technical Details for CVE-2025-49690
Vulnerability Analysis
The Capability Access Management Service (camsvc) brokers application access to sensitive device capabilities such as the camera, microphone, and location services. The service manages capability state through shared in-memory structures consulted across multiple threads and client requests. CVE-2025-49690 stems from improper synchronization when these shared resources are read and modified concurrently. An attacker who can issue requests to camsvc from a low-privileged context can race the service into an inconsistent state. Winning the race lets the attacker influence privileged decisions or operations executed by the service, yielding code or token elevation in the service's security context.
Root Cause
The root cause is a classic time-of-check to time-of-use pattern within camsvc. The service validates a capability state or caller property and then acts on the same shared resource without holding a lock across both operations. An attacker thread mutates the resource between the check and the use, invalidating the validation result. The CWE-362 classification confirms the concurrency primitive is missing or insufficient.
Attack Vector
Exploitation requires local access and no prior authentication beyond an interactive or service session that can communicate with camsvc. No user interaction is required. The attack complexity is high because the attacker must reliably win a narrow timing window, typically by issuing parallel capability requests while simultaneously toggling state. Successful exploitation results in privilege elevation from a standard user to a higher-privileged service context.
No public proof-of-concept code or exploitation in the wild has been reported. The vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog.
Detection Methods for CVE-2025-49690
Indicators of Compromise
- Unexpected crashes, restarts, or access violations recorded for the camsvc service in the Windows Application or System event log.
- Anomalous child processes or token manipulation originating from svchost.exe instances hosting the Capability Access Management Service.
- Standard user accounts gaining elevated rights without a corresponding User Account Control elevation event.
Detection Strategies
- Hunt for processes launched by svchost.exe running camsvc that subsequently spawn shells, scripting hosts, or LOLBins.
- Correlate rapid, high-frequency capability access requests from a single low-privileged process with subsequent privilege changes on the same session.
- Apply behavioral detection that flags token impersonation or handle duplication events tied to the Capability Access Management Service.
Monitoring Recommendations
- Enable Windows audit policies for Process Creation (Event ID 4688) and Sensitive Privilege Use to capture privilege transitions.
- Forward Sysmon Event IDs 1, 10, and 25 to a centralized log platform to identify suspicious access to camsvc process memory.
- Track patch compliance on all in-scope Windows builds and alert on hosts that remain unpatched after the July 2025 cumulative update.
How to Mitigate CVE-2025-49690
Immediate Actions Required
- Apply the July 2025 Microsoft security update that addresses CVE-2025-49690 across all affected Windows 10, Windows 11, and Windows Server builds.
- Prioritize patching on multi-user systems, jump hosts, and Remote Desktop Session Host servers where local attackers are most likely to operate.
- Audit local accounts and remove unnecessary interactive logon rights to reduce the population of users able to reach camsvc.
Patch Information
Microsoft published the official advisory and patch references in the Microsoft CVE-2025-49690 Update Guide. Administrators should deploy the corresponding cumulative update for each Windows build listed in the affected products section. No supported configuration is exempt, and the patch is the only complete fix.
Workarounds
- No official Microsoft-supplied workaround exists; the security update is the authoritative remediation.
- Restrict local logon to trusted administrators on high-value systems until patches are deployed.
- Apply application control policies such as Windows Defender Application Control or AppLocker to block unapproved binaries that could stage the race exploit.
# Verify the camsvc-related update is installed on a Windows host
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 10
# Confirm the Capability Access Manager Service state
Get-Service -Name camsvc | Format-List Name, Status, StartType
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
