CVE-2025-27034 is a critical security vulnerability identified in Qualcomm Snapdragon chipsets, stemming from CWE-129: Improper Validation of Array Index. The vulnerability occurs during the process of selecting the Public Land Mobile Network (PLMN) from the SOR (Selected Operator Reject) failed list, where improper bounds checking leads to memory corruption. This flaw affects an extensive list of Qualcomm products, including numerous Snapdragon mobile platforms (from Snapdragon 4 Gen 1 up to Snapdragon 8+ Gen 2), various FastConnect Wi-Fi/Bluetooth combo chips, modem-RF systems, and audio codecs. The improper validation allows an attacker to craft malicious network messages or signals that trigger out-of-bounds memory access, potentially leading to arbitrary code execution or denial of service (device crash). The vulnerability requires no privileges, no user interaction, and can be exploited remotely over the network interface, making it highly dangerous. The CVSS v3.1 base score is 9.8, reflecting its critical impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the broad attack surface and critical severity necessitate urgent mitigation. Qualcomm and device manufacturers must issue patches or firmware updates to validate array indices properly and prevent memory corruption. This vulnerability threatens the security of billions of devices globally, including smartphones, IoT devices, automotive systems, and other embedded platforms using affected Snapdragon components.

For European organizations, the impact of CVE-2025-27034 is substantial due to the widespread use of Qualcomm Snapdragon chipsets in mobile devices, IoT endpoints, and automotive systems. Confidentiality risks include potential unauthorized access to sensitive data stored or transmitted by affected devices. Integrity can be compromised through arbitrary code execution, allowing attackers to manipulate device behavior or implant persistent malware. Availability is at risk as memory corruption can cause device crashes or denial of service, disrupting business operations reliant on mobile communications or connected devices. Critical infrastructure sectors such as telecommunications, automotive, healthcare, and manufacturing that deploy Snapdragon-based devices are particularly vulnerable. The remote, no-interaction exploitation vector increases the likelihood of large-scale attacks, potentially affecting millions of users and devices across Europe. This could lead to data breaches, operational disruptions, and erosion of trust in mobile and IoT technologies. Additionally, regulatory compliance risks arise under GDPR and NIS Directive if personal data or critical services are impacted.

Mitigation of CVE-2025-27034 requires coordinated action between Qualcomm, device manufacturers, mobile network operators, and end users. Qualcomm must release patches or firmware updates that enforce proper array index validation during PLMN selection. Device manufacturers and OEMs should prioritize deploying these updates to all affected devices, including smartphones, IoT modules, and automotive systems. Mobile network operators should monitor network traffic for anomalous patterns indicative of exploitation attempts and consider temporary network-level mitigations such as filtering malformed PLMN selection messages. Organizations should implement robust endpoint detection and response (EDR) solutions to identify suspicious device behavior. Users must be encouraged to promptly install security updates and avoid connecting to untrusted networks. For critical infrastructure, network segmentation and strict access controls can limit the impact of compromised devices. Additionally, security teams should prepare incident response plans specific to mobile and IoT device compromise scenarios. Given the lack of known exploits in the wild, proactive patching and monitoring are the best defenses.