CVE-2025-27076: Qualcomm Aqt1000 Race Condition Flaw

CVE-2025-27076 Overview

CVE-2025-27076 is a memory corruption vulnerability affecting a broad range of Qualcomm firmware components, including FastConnect Wi-Fi/Bluetooth combo chips, Snapdragon compute platforms, and WCD/WSA audio codecs. The flaw stems from a race condition (TOCTOU) during the processing of simultaneous requests via an escape path. A local attacker with low privileges can trigger the race to corrupt memory, leading to compromise of confidentiality, integrity, and availability on the affected device. Qualcomm published fixes as part of the August 2025 Security Bulletin.

Critical Impact
A successful race-condition exploit can corrupt kernel or firmware memory, giving a local attacker a path to privilege escalation and code execution across dozens of Qualcomm chipsets used in mobile, compute, and IoT devices.

Affected Products

Qualcomm FastConnect 6200, 6700, 6800, 6900, and 7800 firmware
Qualcomm Snapdragon 7c, 7c Gen 2, 7c+ Gen 3, 8c, 8cx, 8cx Gen 2 5G, and 8cx Gen 3 compute platform firmware
Qualcomm WCD9340/9341/9370/9375/9380/9385 and WSA8810/8815/8830/8835/8840/8845/8845H audio codec firmware, plus QCA6391/6420/6430, QCM5430/6490, QCS5430/6490, AQT1000, SM6250, SC8180X+SDX55, SC8380XP, and Video Collaboration VC3 Platform firmware

Discovery Timeline

2025-08-06 - CVE-2025-27076 published to NVD
August 2025 - Qualcomm releases security patch via the August 2025 Security Bulletin
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-27076

Vulnerability Analysis

CVE-2025-27076 is a concurrency defect classified under [CWE-367] Time-of-Check to Time-of-Use (TOCTOU) race condition. The flaw occurs when the firmware processes simultaneous requests reaching the same escape path handler. Between the validation of request state and its use, a second thread can mutate the underlying data structure, producing memory corruption in the firmware's control flow or heap.

Because the vulnerable surface sits inside firmware components shared by Wi-Fi, Bluetooth, audio codec, and compute subsystems, exploitation impacts the trust boundary between userspace and lower-level firmware execution. The attack vector is local, and exploitation requires low privileges but high attack complexity because the attacker must reliably win the race window.

Root Cause

The root cause is inadequate synchronization around a shared resource accessed by an escape-path code branch. When two or more requests execute concurrently, a validated pointer or state variable becomes stale before it is dereferenced, corrupting memory the firmware later trusts. This class of defect commonly enables attacker-controlled writes when structure fields are reused after a check-then-use sequence.

Attack Vector

A local, authenticated attacker who can invoke firmware request interfaces from userspace issues concurrent requests targeting the escape path. By repeatedly racing the handler, the attacker triggers the memory corruption primitive. Successful exploitation can lead to code execution at firmware or kernel privilege, information disclosure from adjacent memory, or denial of service through crashes of the affected subsystem. No user interaction is required.

Exploitation code has not been publicly released, and no proof-of-concept is currently tracked in vendor advisories. Refer to the Qualcomm August 2025 Security Bulletin for the vendor's technical description.

Detection Methods for CVE-2025-27076

Indicators of Compromise

Unexpected crashes, kernel panics, or watchdog resets originating from Qualcomm Wi-Fi, Bluetooth, audio codec, or compute subsystem drivers.
Repeated dmesg or logcat entries referencing faults inside firmware request handlers or escape-path IOCTLs.
Presence of unsigned or newly deployed local binaries invoking chipset request interfaces at abnormally high frequency.

Detection Strategies

Baseline the rate of chipset request/IOCTL calls per process and alert on processes issuing high-concurrency bursts against firmware interfaces.
Correlate unprivileged process activity with subsequent driver faults, kernel oops events, or firmware reload messages.
Track firmware version fingerprints across the fleet and flag devices running versions predating the Qualcomm August 2025 Security Bulletin fixes.

Monitoring Recommendations

Forward kernel logs, crash dumps, and driver telemetry from affected devices to a centralized log platform for correlation.
Monitor for privilege escalation attempts that follow driver fault events on the same host within short time windows.
Alert on new local processes spawned by low-privileged users that access Qualcomm chipset device nodes.

How to Mitigate CVE-2025-27076

Immediate Actions Required

Inventory endpoints, mobile devices, and embedded platforms using the affected Qualcomm chipsets listed in the advisory.
Apply OEM firmware updates that incorporate Qualcomm's August 2025 Security Bulletin patches as soon as they are available for your device model.
Restrict local access to affected systems and enforce least-privilege policies to reduce the pool of accounts capable of invoking chipset request interfaces.

Patch Information

Qualcomm addressed CVE-2025-27076 in the Qualcomm August 2025 Security Bulletin. OEMs consuming Qualcomm's BSP must integrate the fix and ship it as a firmware or system update. Verify that installed firmware images correspond to the patched baseline for each affected component (FastConnect, Snapdragon compute, WCD/WSA codecs, QCA/QCM/QCS series).

Workarounds

No vendor-supplied workaround exists; patching is the only supported remediation.
Where patches are not yet available, limit installation of untrusted local applications and disable unused chipset-adjacent features (for example, unused radios or audio paths) to reduce the exposed request surface.
Enforce application allowlisting on managed endpoints to block execution of unknown local binaries that could invoke the vulnerable escape path.

bash

# Verify Qualcomm firmware/build fingerprint on Android-based devices
adb shell getprop ro.build.fingerprint
adb shell getprop ro.vendor.build.security_patch
# Confirm the security patch level is 2025-08-01 or later