CVE-2025-47373: Qualcomm Fastconnect Buffer Overflow

CVE-2025-47373 Overview

CVE-2025-47373 is an out-of-bounds write vulnerability affecting a wide range of Qualcomm chipset firmware. The vulnerability occurs due to memory corruption when accessing buffers with invalid length during Trusted Application (TA) invocation. This flaw exists within the Trusted Execution Environment (TEE) boundary handling, where improper validation of buffer lengths passed during TA invocations can lead to memory corruption.

An attacker with local access and low privileges could exploit this vulnerability to achieve code execution, compromise confidentiality, integrity, and availability of the affected device. The vulnerability impacts numerous Qualcomm products including Snapdragon mobile platforms, FastConnect wireless modules, automotive chipsets, and IoT devices.

Critical Impact

Local attackers can achieve arbitrary code execution by exploiting improper buffer length validation during Trusted Application invocation, potentially leading to complete device compromise.

Affected Products

• Qualcomm Snapdragon 8 Gen 1/2/3 Mobile Platforms
• Qualcomm FastConnect 6200/6700/6900/7800 Firmware
• Qualcomm SA8155P/SA8195P/SA8255P/SA8295P Automotive Platforms
• Qualcomm WCN6450/WCN6650/WCN6755/WCN7860/WCN7880 Series
• Qualcomm Snapdragon X32/X35/X72/X75 5G Modem-RF Systems
• Qualcomm QCM/QCS Series (QCM4490, QCM6490, QCS8550)

Discovery Timeline

• March 2, 2026 - CVE-2025-47373 published to NVD
• March 4, 2026 - Last updated in NVD database

Technical Details for CVE-2025-47373

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-Bounds Write), indicating that the firmware writes data past the intended buffer boundaries. The flaw exists in the Trusted Execution Environment's handling of buffer parameters during Trusted Application invocations.

When a TA invocation occurs, buffer lengths are passed as parameters to define memory boundaries for data operations. The vulnerable code path fails to properly validate these length parameters before performing memory operations, allowing an attacker to specify invalid buffer lengths that cause the system to write beyond allocated memory regions.

The local attack vector requires the attacker to have some level of access to the device, though only low privileges are needed to trigger the vulnerability. No user interaction is required, making this a practical attack vector for malware or malicious applications that have gained initial access to the device.

Root Cause

The root cause is improper validation of buffer length parameters passed during Trusted Application invocation within the Qualcomm TEE implementation. When a client application communicates with a Trusted Application, it passes shared memory buffers with associated length descriptors. The vulnerable code path does not adequately verify that these length values correspond to the actual allocated buffer sizes, allowing memory corruption to occur when the TA processes data using the attacker-controlled length values.

Attack Vector

The attack requires local access to the affected device. An attacker could exploit this vulnerability through a malicious application or by leveraging another vulnerability to gain initial code execution. The exploitation flow involves:

1. An attacker crafts a malicious TA invocation request with manipulated buffer length parameters
2. The request is passed to the TEE without proper length validation
3. Memory operations within the TA use the invalid length, causing out-of-bounds writes
4. The memory corruption can be leveraged for code execution or privilege escalation within the secure world

The vulnerability does not require user interaction and can be triggered programmatically once the attacker has local access with low privileges on the device.

Detection Methods for CVE-2025-47373

Indicators of Compromise

• Unexpected crashes or reboots in devices using affected Qualcomm chipsets
• Anomalous memory access patterns in TEE-related processes
• Suspicious applications making frequent TA invocation calls with unusual parameters
• System instability following execution of untrusted applications

Detection Strategies

• Monitor for abnormal TEE-related system calls and TA invocation patterns
• Implement runtime integrity checking for firmware components
• Deploy endpoint detection solutions capable of monitoring low-level system behavior
• Review application permissions and restrict access to TEE interfaces for untrusted apps

Monitoring Recommendations

• Enable verbose logging for TEE operations where supported by device firmware
• Utilize mobile device management (MDM) solutions to track firmware versions and ensure timely updates
• Implement behavioral analysis to detect applications exhibiting exploitation attempts
• Conduct regular firmware integrity verification on critical devices

How to Mitigate CVE-2025-47373

Immediate Actions Required

• Apply firmware updates from Qualcomm and device OEMs as soon as available
• Review and audit applications with access to TEE interfaces
• Restrict installation of applications from untrusted sources
• Implement network segmentation for IoT and automotive devices using affected chipsets
• Monitor Qualcomm security bulletins for additional guidance

Patch Information

Qualcomm has addressed this vulnerability in their March 2026 Security Bulletin. Organizations should consult the Qualcomm Security Bulletin March 2026 for specific patch details and affected firmware versions.

Device manufacturers (OEMs) typically integrate Qualcomm security patches into their firmware updates. End users should check with their device manufacturer for availability of security updates addressing CVE-2025-47373.

Workarounds

• Limit installation of applications to trusted sources (official app stores)
• Disable or restrict developer options and debugging interfaces on production devices
• Implement application sandboxing and permission restrictions where possible
• For automotive and IoT deployments, consider network-level isolation of affected devices until patches are applied

# Example: Check firmware version on Android devices
adb shell getprop ro.build.fingerprint
adb shell getprop ro.vendor.build.security_patch

# Verify Qualcomm chipset information
adb shell cat /sys/devices/soc0/soc_id
adb shell cat /sys/devices/soc0/chip_name