CVE-2025-47391: Qualcomm Wcn3988 Buffer Overflow Flaw

CVE-2025-47391 Overview

CVE-2025-47391 is a stack-based buffer overflow (CWE-121) vulnerability affecting numerous Qualcomm chipsets and firmware. The vulnerability occurs during the processing of a frame request from user input, leading to memory corruption that could allow an attacker with local access to achieve code execution or escalate privileges on vulnerable devices.

This vulnerability impacts a wide range of Qualcomm products including Snapdragon mobile platforms, FastConnect connectivity components, WCN wireless connectivity chips, automotive platforms, and IoT devices. Given the broad deployment of these chipsets in smartphones, vehicles, and embedded systems, the potential attack surface is substantial.

Critical Impact

Local attackers with low privileges can exploit this stack-based buffer overflow to potentially execute arbitrary code, gain elevated privileges, or cause denial of service on affected Qualcomm-based devices.

Affected Products

• Qualcomm Snapdragon 8 Elite, Snapdragon 8 Gen 1/2/3, Snapdragon 8+ Gen 1/2 Mobile Platforms
• Qualcomm Snapdragon 7 Gen 1, Snapdragon 7+ Gen 2, Snapdragon 7s Gen 3, Snapdragon 6 Gen 1/3/4, Snapdragon 4 Gen 2 Mobile Platforms
• Qualcomm FastConnect 6200, 6700, 6900, 7800 Connectivity Components
• Qualcomm WCN3950, WCN3988, WCN6450, WCN6650, WCN6755, WCN7860/7861/7880/7881 Series
• Qualcomm Automotive Platforms (SA7255P, SA7775P, SA8255P, SA8620P, SA8770P, SA9000P, LemansAU)
• Qualcomm QCM/QCS Series (QCM4490, QCM5430, QCM6490, QCS4490, QCS8550)
• Qualcomm WSA Audio Amplifiers (WSA8810, WSA8815, WSA8830, WSA8832, WSA8835, WSA8840, WSA8845)

Discovery Timeline

• April 6, 2026 - CVE-2025-47391 published to NVD
• April 8, 2026 - Last updated in NVD database

Technical Details for CVE-2025-47391

Vulnerability Analysis

The vulnerability resides in the frame request processing logic within affected Qualcomm firmware. When user-supplied data is processed during a frame request operation, insufficient bounds checking allows data to overflow the stack buffer, corrupting adjacent memory structures. This memory corruption can overwrite critical stack data including return addresses and saved frame pointers.

The attack requires local access to the device, meaning an attacker would need to execute code on the target system (such as through a malicious application or after gaining initial access through another vector). Once triggered, successful exploitation could allow the attacker to hijack program execution flow, potentially leading to arbitrary code execution with the privileges of the affected component.

Given that many of the affected components operate at a firmware or kernel driver level, successful exploitation could provide an attacker with elevated system privileges beyond what their initial access would normally permit.

Root Cause

The root cause is a stack-based buffer overflow (CWE-121) in the frame request handling code. The vulnerable code path fails to properly validate the size of user-controlled input before copying it into a fixed-size stack buffer. This allows an attacker to supply data that exceeds the buffer capacity, causing adjacent stack memory to be overwritten with attacker-controlled values.

Stack-based buffer overflows are particularly dangerous because the stack contains both data and control flow information (return addresses), making code execution exploitation more straightforward compared to heap-based overflows.

Attack Vector

The vulnerability requires local access to the affected device. An attacker would need to:

1. Gain initial access to a device running vulnerable Qualcomm firmware (e.g., through a malicious application installation)
2. Craft a malicious frame request with oversized or specially crafted input data
3. Trigger the vulnerable code path to process the malicious request
4. Exploit the resulting memory corruption to achieve code execution or privilege escalation

The attack does not require user interaction once the attacker has local code execution capability. The vulnerability affects the confidentiality, integrity, and availability of the system, as successful exploitation could allow reading sensitive data, modifying system state, or causing system crashes.

Detection Methods for CVE-2025-47391

Indicators of Compromise

• Unusual system crashes or reboots on Qualcomm-based devices, particularly related to wireless or audio components
• Evidence of unexpected privilege escalation by applications with previously limited permissions
• Anomalous memory access patterns in firmware logs or kernel crash dumps indicating stack corruption
• Suspicious local applications attempting to interact with low-level Qualcomm drivers or firmware interfaces

Detection Strategies

• Implement endpoint detection and response (EDR) solutions capable of monitoring memory corruption attempts and abnormal process behavior
• Deploy mobile threat defense solutions on Android devices using affected Snapdragon platforms to detect malicious applications
• Monitor device firmware version information to identify unpatched systems within your fleet
• Utilize kernel integrity monitoring tools to detect unauthorized modifications resulting from exploitation

Monitoring Recommendations

• Enable detailed logging on device management platforms to track firmware versions across mobile device fleets
• Implement network-based anomaly detection to identify potentially compromised devices exhibiting unusual behavior
• Configure mobile device management (MDM) solutions to alert on devices running outdated firmware that lacks this security patch
• Establish baseline behavior profiles for Qualcomm-based devices to detect deviations that may indicate compromise

How to Mitigate CVE-2025-47391

Immediate Actions Required

• Review Qualcomm's April 2026 Security Bulletin to determine if your devices are affected and identify available patches
• Prioritize firmware updates for devices in sensitive environments or those with elevated risk profiles
• Implement application whitelisting on affected devices to reduce the risk of malicious code gaining local execution
• Consider network segmentation to limit the potential impact of compromised IoT or automotive devices

Patch Information

Qualcomm has addressed this vulnerability in their April 2026 Security Bulletin. Affected device manufacturers (OEMs) will release firmware updates incorporating the fix according to their respective update schedules. For mobile devices, patches will typically be delivered through Android security updates. For automotive and IoT platforms, contact your device vendor for specific patch availability timelines.

Refer to the Qualcomm April 2026 Security Bulletin for the complete list of affected products and patch information.

Workarounds

• Until patches are available, restrict installation of applications from untrusted sources to minimize the risk of malicious local code execution
• Enable additional device security features such as SE Linux enforcement and verified boot where available
• For enterprise environments, implement mobile application management (MAM) policies to control which applications can be installed on affected devices
• Monitor Qualcomm and OEM security advisories for updated patch availability and apply updates promptly when released

# Example: Check device chipset on Android (for inventory purposes)
adb shell getprop ro.hardware
adb shell getprop ro.board.platform
# Review output to identify affected Snapdragon/Qualcomm platforms
# Cross-reference with Qualcomm April 2026 Security Bulletin affected products list