CVE-2025-21443: Qualcomm Qam8255p Buffer Overflow Flaw

CVE-2025-21443 Overview

CVE-2025-21443 is a memory corruption vulnerability in the Ethernet Audio Video Bridging (eAVB) component of Qualcomm firmware. The flaw occurs while processing message content and is classified under [CWE-120] (Buffer Copy without Checking Size of Input). A local attacker with low privileges can trigger the corruption without user interaction, leading to compromise of confidentiality, integrity, and availability. The vulnerability affects a broad set of Qualcomm automotive and connectivity platforms, including Snapdragon Auto SA8155P, SA8295P, SA8775P, and QCA6xxx Wi-Fi chipsets. Qualcomm addressed the issue in its April 2025 Security Bulletin.

Critical Impact
A local, authenticated attacker can corrupt kernel or firmware memory in eAVB, achieving arbitrary code execution or denial of service on Qualcomm automotive and connectivity SoCs.

Affected Products

Qualcomm Snapdragon Auto platforms (SA8155P, SA8195P, SA8255P, SA8295P, SA8540P, SA8620P, SA8650P, SA8770P, SA8775P, SA9000P)
Qualcomm QAM automotive modules (QAM8255P, QAM8295P, QAM8620P, QAM8650P, QAM8775P, QAMSRV1H, QAMSRV1M)
Qualcomm QCA connectivity chipsets (QCA6574A, QCA6574AU, QCA6595, QCA6595AU, QCA6688AQ, QCA6696, QCA6698AQ)

Discovery Timeline

2025-04-07 - CVE-2025-21443 published to NVD following Qualcomm's April 2025 Security Bulletin
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-21443

Vulnerability Analysis

The vulnerability resides in Qualcomm's eAVB (Ethernet Audio Video Bridging) implementation. eAVB provides deterministic, low-latency streaming of audio and video across Ethernet networks, commonly used in automotive infotainment and ADAS domains. During processing of incoming message content, the affected code path copies data into a memory buffer without adequately validating input size against buffer bounds.

The resulting memory corruption can overwrite adjacent structures, function pointers, or control data within the eAVB driver context. Because eAVB executes with elevated privileges within the SoC's runtime, successful exploitation compromises the confidentiality, integrity, and availability of the affected system. On automotive platforms this driver processes streaming traffic critical to vehicle telematics and infotainment functionality.

Root Cause

The root cause is a classic [CWE-120] buffer copy without checking the size of input. The eAVB message handler trusts a length or content field supplied by the caller and performs a copy operation into a fixed-size destination buffer. When the input exceeds the destination capacity, memory beyond the buffer boundary is overwritten.

Attack Vector

Exploitation requires local access with low privileges on the affected device. An attacker submits a crafted eAVB message through an application or interface that reaches the vulnerable handler. No user interaction is needed. The vulnerability manifests entirely within the local trust boundary of the SoC; remote network exploitation is not indicated in Qualcomm's advisory.

Because no verified proof-of-concept code is publicly available, detailed exploitation primitives are not reproduced here. See the Qualcomm Security Bulletin April 2025 for vendor-supplied context.

Detection Methods for CVE-2025-21443

Indicators of Compromise

Unexpected crashes, panics, or restarts of the eAVB driver or dependent audio/video streaming services on Qualcomm-based automotive head units
Kernel or firmware log entries referencing invalid memory access, stack canary failures, or aborts originating from eAVB message-processing functions
Anomalous local processes issuing repeated or malformed eAVB ioctl or IPC calls to the driver

Detection Strategies

Inventory devices using the affected Qualcomm SoC and firmware CPEs listed in the NVD entry, then verify firmware build against Qualcomm's April 2025 bulletin
Monitor system logs and crash telemetry from automotive gateways and infotainment units for repeated faults in eAVB code paths
Correlate local privilege escalation attempts with subsequent driver instability to identify potential exploitation chains

Monitoring Recommendations

Ingest device crash reports and kernel logs from vehicle and IoT fleets into a centralized data lake for retrospective hunting on eAVB-related faults
Baseline normal eAVB messaging behavior and alert on deviations such as oversized payloads or unusual message frequency
Track firmware versions across the fleet and flag any device that has not been updated to the April 2025 patched build

How to Mitigate CVE-2025-21443

Immediate Actions Required

Apply the firmware update supplied by the OEM or Tier 1 integrator that incorporates Qualcomm's April 2025 patch for the eAVB component
Restrict local access to affected devices; limit which applications and users can send messages to the eAVB driver
Audit installed applications on automotive head units and IoT gateways for unknown or unsigned software with local privileges

Patch Information

Qualcomm published the fix in the Qualcomm Security Bulletin April 2025. OEMs must integrate the corrected firmware into their downstream builds and deliver it to end devices through their standard update channels. Because affected SoCs are widely deployed in automotive platforms, patch availability depends on the vehicle manufacturer or device integrator.

Workarounds

If patching is not immediately feasible, disable or unload the eAVB driver on devices where audio/video bridging is not required
Enforce strict application allow-listing to prevent untrusted local code from reaching the vulnerable driver interface
Segment automotive and IoT networks so that a compromised endpoint cannot pivot to additional Qualcomm-based devices

bash

# Verify Qualcomm firmware build after applying the April 2025 patch
# (example - actual command depends on OEM platform)
getprop ro.build.version.security_patch
cat /proc/version