CVE-2025-27708 Overview
CVE-2025-27708 is an out-of-bounds read vulnerability [CWE-125] in the firmware of certain Intel(R) Converged Security and Management Engine (CSME) components. The flaw resides within Ring 0 (Kernel) execution context and may allow information disclosure. A local adversary with high privileges can trigger the condition through a low-complexity attack that requires no user interaction. Successful exploitation impacts the confidentiality of the affected system, while integrity and availability remain unaffected.
Critical Impact
A privileged local attacker can read out-of-bounds memory in CSME firmware running at Ring 0, exposing sensitive information processed by the management engine.
Affected Products
- Intel(R) Converged Security and Management Engine (CSME) Firmware — specific affected versions listed in Intel Security Advisory SA-01315
- Platforms shipping with vulnerable CSME firmware images
- Systems where CSME firmware has not been updated to the fixed release
Discovery Timeline
- 2026-02-10 - CVE-2025-27708 published to NVD
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2025-27708
Vulnerability Analysis
The vulnerability is an out-of-bounds read [CWE-125] in CSME firmware that executes within the kernel privilege level of the management engine. CSME runs as an isolated subsystem alongside the main CPU and processes security-sensitive operations such as platform attestation, firmware TPM, and provisioning data.
When the affected firmware processes specific inputs, it reads memory outside the bounds of an intended buffer. The data returned to the caller can include adjacent memory contents, which may contain secrets handled by CSME. Because the read occurs in Ring 0 of the management engine, exposed data may originate from privileged firmware structures.
The Exploit Prediction Scoring System rates this issue at 0.017%, reflecting low observed exploitation likelihood. No public proof-of-concept is currently available.
Root Cause
The root cause is missing or incorrect boundary validation when CSME firmware accesses an indexed memory region. The firmware trusts an offset or length value without verifying it against the actual buffer size, allowing the read pointer to move past the allocated range.
Attack Vector
Exploitation requires local access with high privileges on the host. The attacker interacts with CSME through interfaces exposed to system software, such as the Host Embedded Controller Interface (HECI/MEI). By issuing a crafted command sequence, the attacker triggers the firmware code path that performs the out-of-bounds read and returns leaked memory in the response.
No verified exploit code is publicly available. The vulnerability mechanism is described in the Intel Security Advisory SA-01315.
Detection Methods for CVE-2025-27708
Indicators of Compromise
- No public indicators of compromise have been published for CVE-2025-27708.
- Unusual sequences of HECI/MEI commands from non-administrative tooling on managed endpoints.
- CSME firmware version strings that do not match the fixed releases listed in Intel SA-01315.
Detection Strategies
- Inventory CSME firmware versions across the fleet using vendor management tools and compare against the fixed versions in Intel's advisory.
- Monitor for processes that load Intel MEI drivers and issue raw command buffers, particularly outside of expected administrative workflows.
- Correlate local privilege escalation events with subsequent access to MEI device interfaces such as \\.\MEI on Windows or /dev/mei0 on Linux.
Monitoring Recommendations
- Enable endpoint logging for driver load events related to MEIx64.sys and the Linux mei_me kernel module.
- Track firmware version telemetry from manageability agents and alert on hosts that fall behind the patched baseline.
- Audit administrative tool execution on endpoints that hold sensitive data processed by CSME, including fTPM-protected keys.
How to Mitigate CVE-2025-27708
Immediate Actions Required
- Identify systems running affected Intel CSME firmware using OEM management utilities or Intel CSME version queries.
- Apply the firmware update referenced in Intel Security Advisory SA-01315 through the OEM-supplied BIOS or firmware package.
- Restrict local administrative access on systems that cannot be immediately patched, since exploitation requires high privileges.
Patch Information
Intel has published mitigation guidance in Intel Security Advisory SA-01315. OEM vendors distribute the fixed CSME firmware as part of BIOS/UEFI updates. Administrators should obtain updates from the system manufacturer that correspond to the affected platform generation.
Workarounds
- Limit local administrator and SYSTEM-level access through least-privilege policies until firmware can be updated.
- Disable unused CSME-exposed features in BIOS where supported by the platform, such as Intel AMT, when not operationally required.
- Apply OS-level driver restrictions to prevent untrusted code from interacting with the MEI device.
# Configuration example: query CSME firmware version on Linux
cat /sys/class/mei/mei0/fw_ver
# Restrict MEI device access to root only
chmod 600 /dev/mei0
chown root:root /dev/mei0
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
