CVE-2025-20037 Overview
CVE-2025-20037 is a time-of-check time-of-use (TOCTOU) race condition [CWE-367] in firmware for some Intel(R) Converged Security and Management Engine (CSME). The flaw allows a privileged user with local access to potentially escalate privileges on affected systems. Intel disclosed the issue in advisory SA-01280.
The vulnerability carries a CVSS 4.0 score of 6.8 and requires local access, high privileges, and the presence of specific attack conditions. Successful exploitation impacts integrity and availability of the platform and downstream subsystems. No public exploit or in-the-wild activity has been reported.
Critical Impact
A local, privileged attacker who wins a race window in CSME firmware can subvert firmware integrity and gain elevated control below the operating system boundary.
Affected Products
- Intel(R) Converged Security and Management Engine (CSME) firmware — specific versions listed in Intel advisory SA-01280
- Platforms shipping affected CSME firmware images
- Systems that have not applied the Intel firmware update addressing SA-01280
Discovery Timeline
- 2025-08-12 - CVE-2025-20037 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-20037
Vulnerability Analysis
CVE-2025-20037 is a TOCTOU race condition inside Intel CSME firmware. The Converged Security and Management Engine runs as an isolated coprocessor that handles platform security functions, including firmware measurement, secure boot support, and manageability services. A privileged user on the host can interact with CSME through defined interfaces to trigger the race.
The defect appears when the firmware validates a resource or parameter and then uses that same resource in a later operation. Between the check and the use, an attacker with sufficient local privilege can modify the state observed by the firmware. This desynchronization causes the firmware to act on attacker-controlled data that never passed validation.
The outcome maps to integrity and availability impact on the CSME itself and on subsystems that trust its decisions. Confidentiality is not directly affected according to the CVSS vector.
Root Cause
The root cause is non-atomic handling of security-relevant data in CSME firmware. Validation logic and consumption logic operate on shared state without adequate locking or double-fetch protection, which is the defining characteristic of [CWE-367].
Attack Vector
Exploitation requires local access and pre-existing high privileges on the host. The attacker must also meet specific attack conditions and win a narrow timing window, which raises attack complexity. No user interaction is required. The vulnerability manifests through legitimate CSME interfaces rather than through arbitrary code running inside the ME itself.
Because no verified proof-of-concept has been published, technical exploitation details remain limited to Intel's advisory. See the Intel Security Advisory SA-01280 for firmware version specifics.
Detection Methods for CVE-2025-20037
Indicators of Compromise
- No public indicators of compromise have been released for CVE-2025-20037.
- Unexpected changes to CSME firmware version strings reported by MEInfo or platform management tools.
- Anomalous Host Embedded Controller Interface (HECI/MEI) activity originating from administrative processes.
Detection Strategies
- Inventory CSME firmware versions across the fleet and compare against the fixed versions listed in Intel SA-01280.
- Monitor for administrative processes issuing repeated or unusual MEI/HECI commands, which is atypical for standard workloads.
- Alert on unauthorized use of Intel management utilities such as FWUpdLcl or vendor BIOS update tools outside of change windows.
Monitoring Recommendations
- Collect firmware version telemetry through endpoint management agents and centralize it in a SIEM or data lake for drift analysis.
- Correlate local privilege escalation alerts on endpoints with subsequent access to platform management interfaces.
- Track vendor OEM advisories, since CSME firmware ships through system manufacturers rather than directly from Intel.
How to Mitigate CVE-2025-20037
Immediate Actions Required
- Apply the Intel CSME firmware updates referenced in advisory SA-01280 through your OEM's BIOS or firmware update channel.
- Restrict administrative privileges on endpoints, since exploitation requires a privileged local user.
- Audit which accounts and processes can access MEI/HECI interfaces and reduce that surface where possible.
Patch Information
Intel has published fixed CSME firmware versions in Intel Security Advisory SA-01280. OEMs typically redistribute these updates as BIOS or firmware packages. Validate the fixed version numbers with the specific platform vendor before deployment.
Workarounds
- No official software workaround exists — firmware update is the supported remediation.
- Enforce least privilege and remove local administrative rights from standard users to eliminate the privileged-access precondition.
- Enable measured boot and monitor platform attestation results so that unexpected CSME state changes surface quickly.
# Verify CSME firmware version on Linux using intel-sa-00086-tool or MEI sysfs
cat /sys/class/mei/mei0/fw_ver
# On Windows, use Intel CSME Version Detection Tool or MEInfoWin
MEInfoWin.exe -FWVer
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
