CVE-2025-21468 Overview
CVE-2025-21468 is an out-of-bounds write vulnerability [CWE-787] affecting a wide range of Qualcomm chipset firmware components. The flaw occurs when a driver reads a response from the firmware (FW) and appends a null terminator using a buffer size that the FW can modify concurrently. This race between the FW updating the size and the driver writing the null character results in memory corruption. Qualcomm published the fix in its May 2025 security bulletin, and the issue impacts Snapdragon mobile, compute, automotive, wearable, XR, IoT, and FastConnect Wi-Fi/Bluetooth platforms.
Critical Impact
Local low-privileged code can corrupt kernel or driver memory across hundreds of Qualcomm-based devices, enabling elevation of privilege and compromise of confidentiality, integrity, and availability.
Affected Products
- Qualcomm Snapdragon mobile platforms including Snapdragon 8 Gen 1/2/3, Snapdragon 888/888+, and Snapdragon 4/7/8 series firmware
- FastConnect 6200/6700/6900/7800 and QCA-series connectivity firmware (Wi-Fi/Bluetooth)
- Automotive, XR, wearable, and IoT platforms including SA8295P, Snapdragon AR1/AR2 Gen 1, Snapdragon W5+ Gen 1, and Robotics RB2/RB5
Discovery Timeline
- 2025-05-06 - CVE-2025-21468 published to NVD
- May 2025 - Qualcomm publishes patch in the Qualcomm Security Bulletin May 2025
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-21468
Vulnerability Analysis
The vulnerability is a classic out-of-bounds write triggered by a time-of-check to time-of-use (TOCTOU) condition between a host driver and Qualcomm firmware. The driver reads a response buffer from the FW and then writes a terminating null byte at an index derived from a size value that the FW itself controls. If the FW mutates that size value between the driver's validation and the null-write, the driver writes past the allocated buffer boundary. The resulting corruption occurs in a privileged driver context, producing high impact on confidentiality, integrity, and availability of the affected system.
Root Cause
The root cause is trusting a shared, mutable size field without capturing an immutable local copy before it is used for pointer arithmetic. The driver treats the FW-supplied buffer length as stable, but the FW can update it during the driver's processing window. When the driver then executes buffer[size] = '\0', the effective index may exceed the actual allocation, causing an out-of-bounds write [CWE-787].
Attack Vector
Exploitation requires local access with low privileges and no user interaction. An attacker with the ability to interact with the affected driver interface, or to influence firmware behavior through an adjacent malicious component, can steer the size value used by the driver. Successful exploitation corrupts kernel-adjacent memory and can be chained to achieve privilege escalation on the host operating system. No public proof-of-concept is available, and the vulnerability is not listed in the CISA KEV catalog.
No verified exploit code is publicly available for CVE-2025-21468.
Refer to the Qualcomm May 2025 Security Bulletin for vendor-provided
technical details on the affected driver and firmware interface.
Detection Methods for CVE-2025-21468
Indicators of Compromise
- Unexpected kernel panics, driver crashes, or watchdog resets referencing Qualcomm connectivity, audio, or modem drivers
- Kernel log entries indicating heap or stack corruption near FW response-handling paths
- Devices running Qualcomm firmware predating the May 2025 security bulletin patch level
Detection Strategies
- Inventory endpoints, mobile devices, automotive units, and IoT gateways to identify Qualcomm components listed in the affected product set
- Correlate device build fingerprints and vendor security patch levels against the May 2025 Qualcomm bulletin
- Monitor for repeated driver faults or firmware reload events that could indicate exploitation attempts targeting the FW response path
Monitoring Recommendations
- Centralize mobile and IoT device telemetry, including crash dumps and patch level attestation, into a security data lake for longitudinal analysis
- Alert on anomalous privilege transitions or module loads following driver crash events on Snapdragon-based endpoints
- Track vendor advisories and OEM downstream patch releases, since Qualcomm patches must be integrated by device manufacturers before reaching end users
How to Mitigate CVE-2025-21468
Immediate Actions Required
- Apply the Qualcomm May 2025 security patch level to all affected devices as soon as OEM firmware updates are available
- Prioritize patching of high-value assets such as automotive head units, industrial IoT gateways, and executive mobile devices
- Restrict installation of untrusted applications on affected devices to reduce local attack surface
Patch Information
Qualcomm addressed CVE-2025-21468 in the Qualcomm Security Bulletin May 2025. Downstream OEMs such as Android device manufacturers, automotive vendors, and IoT integrators must ship the corresponding firmware update through their own release channels. Verify the vendor security patch level on each device to confirm remediation.
Workarounds
- No official workaround is published; patching is the only supported remediation
- Disable or unload affected connectivity and peripheral drivers where operationally feasible until firmware updates land
- Enforce application allowlisting and mobile device management policies to limit local code execution on unpatched devices
# Example: verify Android security patch level on an affected device
adb shell getprop ro.build.version.security_patch
# Confirm the returned date is 2025-05-01 or later before considering the device patched
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
