CVE-2025-21429 is a buffer over-read vulnerability classified under CWE-126, discovered in numerous Qualcomm Snapdragon platforms and wireless connectivity modules. The vulnerability manifests during the process of connecting a wireless station (STA) to an access point (AP) when the device initiates an ADD TS (Traffic Stream) request, a step in the Wi-Fi Quality of Service (QoS) negotiation. Improper handling of this request leads to memory corruption due to reading beyond allocated buffer boundaries. This flaw can be triggered remotely over the network without requiring authentication or user interaction, making it highly exploitable. The affected products span a vast array of Qualcomm chipsets, including LTE modems, 5G modems, automotive platforms, wearable platforms, and various FastConnect wireless modules, covering many Snapdragon mobile platforms from older generations to the latest Snapdragon 8 Gen 3. The vulnerability can cause denial of service (DoS) conditions by crashing the wireless subsystem or the entire device, impacting availability. The CVSS v3.1 score of 7.5 reflects the network attack vector, low attack complexity, no privileges required, no user interaction, and a high impact on availability, though confidentiality and integrity are not affected. No public exploits have been reported yet, but the extensive product footprint and ease of exploitation make this a significant threat. Qualcomm has not yet published patches, so mitigation currently relies on network-level controls and monitoring. The vulnerability was reserved in December 2024 and published in April 2025, indicating recent discovery and disclosure.

This vulnerability poses a significant risk to organizations and end-users relying on Qualcomm Snapdragon-based devices, which include a large portion of smartphones, automotive infotainment systems, IoT devices, and wearable technology worldwide. The primary impact is denial of service, where an attacker can remotely trigger memory corruption leading to device crashes or wireless subsystem failures, resulting in loss of connectivity or device unavailability. This can disrupt critical communications, especially in automotive or industrial IoT contexts where Snapdragon platforms are embedded. The broad range of affected products means that many device types and manufacturers are potentially vulnerable, increasing the attack surface. Enterprises with mobile fleets, telecommunication providers, and automotive manufacturers could face operational disruptions. Although confidentiality and integrity are not directly compromised, the availability impact alone can cause significant business interruptions, safety risks in automotive scenarios, and degraded user experience. The lack of required privileges or user interaction lowers the barrier for attackers to exploit this flaw remotely, increasing the likelihood of attacks once exploit code becomes available.

1. Monitor Qualcomm's official security advisories and promptly apply firmware and software updates once patches are released for affected Snapdragon platforms and wireless modules. 2. Implement network-level protections such as Wi-Fi intrusion detection/prevention systems (IDS/IPS) to detect and block malformed or suspicious ADD TS requests that could trigger the vulnerability. 3. For enterprise environments, segment wireless networks and restrict access to critical systems to minimize exposure. 4. Collaborate with device manufacturers and vendors to ensure timely patch deployment across all affected devices in the organization’s inventory. 5. Employ anomaly detection tools to monitor for unusual wireless connection behaviors indicative of exploitation attempts. 6. In automotive and IoT deployments, consider fallback communication methods or redundancy to maintain availability if devices become unresponsive. 7. Educate security teams about this vulnerability to prepare for incident response related to potential denial of service events. 8. Where possible, disable or restrict QoS features related to ADD TS requests temporarily until patches are applied, balancing functionality and security. 9. Engage with Qualcomm support channels for guidance on interim mitigations specific to device models in use.