CVE-2025-27069: Qualcomm Fastconnect 6900 Buffer Overflow

CVE-2025-27069 Overview

CVE-2025-27069 is a memory corruption vulnerability affecting multiple Qualcomm firmware components, including FastConnect connectivity chips, the SC8380XP compute platform, and WCD/WSA audio codecs. The flaw occurs while processing Device Driver Interface (DDI) command calls and is categorized under [CWE-822: Untrusted Pointer Dereference]. A local, low-privileged attacker who can issue crafted DDI commands can trigger memory corruption in the driver, potentially leading to arbitrary code execution or full compromise of the affected component. Qualcomm disclosed the issue in its August 2025 security bulletin.

Critical Impact
Local exploitation can corrupt driver memory, enabling privilege escalation and complete loss of confidentiality, integrity, and availability on affected Qualcomm-based devices.

Affected Products

Qualcomm FastConnect 6900 and FastConnect 7800 firmware and hardware
Qualcomm SC8380XP compute platform firmware and hardware
Qualcomm WCD9380, WCD9385, WSA8840, WSA8845, and WSA8845H audio codec firmware

Discovery Timeline

2025-08-06 - CVE-2025-27069 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-27069

Vulnerability Analysis

The vulnerability resides in the DDI command processing path of multiple Qualcomm firmware components. When user-space or lower-privileged callers invoke DDI commands, the driver processes pointer or index data supplied through the command interface without adequate validation. This handling condition allows crafted input to corrupt kernel or driver-managed memory. The Qualcomm August 2025 security bulletin identifies the weakness as [CWE-822: Untrusted Pointer Dereference], where the driver dereferences a pointer whose value originated from an untrusted source. Because the affected surface spans connectivity (FastConnect Wi-Fi/Bluetooth), compute (SC8380XP), and audio codecs (WCD/WSA series), the flaw appears in a shared DDI handling routine used across Qualcomm platform drivers.

Root Cause

The root cause is the driver's failure to validate pointer or offset arguments supplied through DDI command calls before dereferencing them. Untrusted input reaches sensitive memory operations, producing out-of-bounds writes or corrupted control structures inside the driver context.

Attack Vector

Exploitation requires local access with low privileges on the target device. An attacker with the ability to open the driver interface and submit DDI commands can craft malicious command payloads that trigger the unchecked dereference. User interaction is not required, and successful exploitation impacts confidentiality, integrity, and availability of the affected component. No public proof-of-concept or in-the-wild exploitation has been reported.

No verified public exploit code is available. Refer to the Qualcomm Security Bulletin August 2025 for authoritative technical details.

Detection Methods for CVE-2025-27069

Indicators of Compromise

Unexpected crashes, kernel panics, or resets involving Qualcomm FastConnect, SC8380XP, or WCD/WSA audio codec drivers.
Anomalous processes opening DDI-related device nodes or issuing high volumes of ioctl-style commands against Qualcomm driver interfaces.
Driver logs showing malformed DDI command payloads or pointer validation failures.

Detection Strategies

Monitor host telemetry for unprivileged processes interacting with kernel driver interfaces exposed by Qualcomm firmware components.
Correlate driver crash dumps with preceding process activity to identify attempts to trigger memory corruption in DDI handlers.
Deploy endpoint behavioral analytics, such as Singularity Endpoint, to flag privilege escalation chains that follow anomalous local driver interactions.

Monitoring Recommendations

Aggregate kernel and driver crash telemetry into a central data lake for long-term correlation across fleets.
Alert on repeated invocations of DDI command interfaces from non-system, unsigned, or newly installed applications.
Track firmware and driver version inventory to confirm which endpoints remain unpatched against the August 2025 Qualcomm bulletin.

How to Mitigate CVE-2025-27069

Immediate Actions Required

Apply the firmware updates published in the Qualcomm Security Bulletin August 2025 as soon as OEM images become available.
Coordinate with device OEMs (laptop, smartphone, and IoT vendors using the affected Qualcomm parts) to obtain platform-specific patches.
Inventory endpoints using FastConnect 6900/7800, SC8380XP, and WCD/WSA codec silicon to prioritize remediation.

Patch Information

Qualcomm released fixes for CVE-2025-27069 in its August 2025 security bulletin. Patches are distributed to OEMs and delivered to end users through standard firmware and platform update channels. Confirm patch application by checking the vendor-specific firmware or driver version after update.

Workarounds

Restrict installation of untrusted third-party applications that could gain local execution and reach the vulnerable DDI interface.
Enforce least-privilege on local accounts and disable interactive access for service or shared user accounts on affected devices.
Where feasible, disable or unload non-essential Qualcomm driver components (for example, unused audio codec paths) until firmware updates are applied.

bash

# Example: verify firmware/driver versions on a Linux-based Qualcomm platform
uname -r
lsmod | grep -Ei 'qca|qcom|wcnss|wcd|wsa'
dmesg | grep -Ei 'qcom|ddi|fastconnect' | tail -n 50