CVE-2025-47340: Qualcomm Fastconnect Buffer Overflow Flaw

CVE-2025-47340 Overview

CVE-2025-47340 is a memory corruption vulnerability affecting multiple Qualcomm firmware components, including FastConnect 6900/7800 connectivity chipsets, audio codecs, and platform-specific processors. The flaw occurs during the processing of an Input/Output Control (IOCTL) call used to retrieve a mapping. An authenticated local attacker with low privileges can trigger the condition to corrupt memory and compromise confidentiality, integrity, and availability on affected devices. The vulnerability is classified under CWE-787 (Out-of-Bounds Write). Qualcomm disclosed the issue in its October 2025 security bulletin.

Critical Impact
A local attacker can trigger out-of-bounds memory writes through a crafted IOCTL request, potentially leading to arbitrary code execution in a privileged context on devices using affected Qualcomm firmware.

Affected Products

Qualcomm FastConnect 6900 and FastConnect 7800 (firmware and hardware)
Qualcomm SC8380XP platform, QCC2072, and WCD9378C/WCD9380/WCD9385 audio codecs
Qualcomm WSA8840/WSA8845/WSA8845H smart speaker amplifiers and X2000077/X2000086/X2000090/X2000092/X2000094 and XG101002/XG101032/XG101039 firmware variants

Discovery Timeline

2025-10-09 - CVE-2025-47340 published to NVD
October 2025 - Qualcomm publishes the October 2025 Security Bulletin with patch guidance
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-47340

Vulnerability Analysis

The vulnerability is a memory corruption flaw within a Qualcomm firmware driver that handles an IOCTL request used to obtain a mapping. When user-space code issues the IOCTL, the driver processes attacker-controllable input without adequate boundary validation. This results in an out-of-bounds write [CWE-787] into kernel or driver-managed memory. Because the affected components span connectivity, audio codec, and platform firmware, the vulnerability surface reaches a broad range of Snapdragon-based devices. Successful exploitation grants an attacker the ability to corrupt adjacent data structures, which can be leveraged for privilege escalation or arbitrary code execution inside the driver context.

Root Cause

The root cause is missing or insufficient validation of parameters passed through the IOCTL interface responsible for retrieving a mapping. The driver writes data outside the intended buffer boundary, corrupting neighboring memory. Insufficient bounds checking on size or offset values supplied by user space is the primary defect.

Attack Vector

Exploitation requires local access and low-privileged code execution on the target device. An attacker with an installed application or a compromised process can open the driver device node and issue a crafted IOCTL call with manipulated parameters. No user interaction is required. The impact scope remains local, but the elevated privileges gained can be used as a pivot for further compromise of the operating system running on top of the affected firmware.

See the Qualcomm Security Bulletin October 2025 for the vendor's technical description.

Detection Methods for CVE-2025-47340

Indicators of Compromise

Unexpected process crashes, kernel panics, or driver faults referencing Qualcomm connectivity, audio codec, or platform firmware drivers
Anomalous IOCTL activity from unprivileged applications targeting Qualcomm driver device nodes
Kernel log entries indicating out-of-bounds writes, memory corruption, or KASAN alerts on affected components

Detection Strategies

Monitor kernel logs (dmesg, logcat) for panics or faults involving affected Qualcomm modules such as FastConnect, WCD, or WSA drivers
Deploy endpoint telemetry that captures process privilege escalation events and unexpected driver interactions from user-installed applications
Correlate device crash reports with recent application installs or updates to identify potentially malicious IOCTL usage

Monitoring Recommendations

Enable mobile device management (MDM) reporting of firmware and patch level status across the fleet to confirm the October 2025 update is applied
Track application behavior for repeated IOCTL calls against Qualcomm device nodes originating from non-system processes
Baseline normal driver interaction patterns and alert on statistical deviations that may indicate exploitation attempts

How to Mitigate CVE-2025-47340

Immediate Actions Required

Apply the Qualcomm October 2025 firmware update on all affected Snapdragon-based devices as soon as OEM builds are available
Inventory devices using FastConnect 6900/7800, SC8380XP, and the listed WCD, WSA, X2000, and XG101 components to prioritize patch rollout
Restrict installation of untrusted applications on affected mobile and embedded devices until patching is complete

Patch Information

Qualcomm has published fixes and downstream guidance in the October 2025 Security Bulletin. Because Qualcomm firmware is delivered through OEM device updates, administrators must confirm that the Original Equipment Manufacturer (OEM) has incorporated the patched components into a shipping firmware release before deployment. Verify device build fingerprints match the vendor-supplied fixed versions.

Workarounds

No vendor-supplied workaround has been published; patching is the only remediation
Reduce exposure by limiting local access on shared or kiosk devices and enforcing application allow-listing through MDM
Where feasible, disable or restrict features that rely on the affected connectivity or audio codec drivers until firmware updates are installed

bash

# Verify Android security patch level and device firmware after OEM update
adb shell getprop ro.build.version.security_patch
adb shell getprop ro.vendor.build.fingerprint
adb shell getprop ro.boot.bootloader