CVE-2025-21433 is a vulnerability identified in a broad range of Qualcomm Snapdragon platforms and related chipsets, characterized as a NULL Pointer Dereference (CWE-476). The flaw occurs specifically when importing a PKCS#8-encoded RSA private key that contains a zero-sized modulus. This malformed input triggers a transient Denial of Service (DoS) condition by causing the affected system to dereference a NULL pointer, leading to a crash or system instability. The vulnerability impacts a vast array of Qualcomm products, including mobile platforms (e.g., Snapdragon 8 Gen series, Snapdragon 7 and 6 series), connectivity modules (FastConnect series), automotive and robotics platforms, and various wireless communication chips. The CVSS v3.1 base score is 6.2, indicating a medium severity level. The attack vector is local (AV:L), requiring the attacker to have local access to the device or system. No privileges are required (PR:N), no user interaction is needed (UI:N), and the impact is limited to availability (A:H) with no confidentiality or integrity effects. The vulnerability does not appear to have known exploits in the wild as of the publication date. The issue stems from improper input validation when handling RSA private keys, which could be exploited by an attacker with local access to cause a denial of service, potentially disrupting device functionality temporarily. Given the extensive list of affected Qualcomm platforms, this vulnerability could affect a wide range of devices, including smartphones, IoT devices, automotive systems, and embedded platforms that utilize these chipsets.

For European organizations, the impact of CVE-2025-21433 primarily revolves around availability disruptions in devices and systems using affected Qualcomm Snapdragon platforms. Enterprises relying on mobile devices, embedded systems, or IoT infrastructure powered by these chipsets could experience transient outages or crashes if an attacker manages to supply a crafted PKCS#8 RSA private key with a zero-sized modulus. While the vulnerability requires local access, scenarios such as compromised internal devices, malicious insiders, or supply chain attacks could enable exploitation. Critical sectors such as telecommunications, automotive, manufacturing, and healthcare that deploy Qualcomm-based embedded systems or mobile devices may face operational interruptions. Although the vulnerability does not compromise confidentiality or integrity, denial of service conditions could degrade service availability, impacting business continuity and user experience. Additionally, given the widespread use of Qualcomm chipsets in consumer and industrial devices, the potential for cascading effects in interconnected systems exists if vulnerable devices are part of larger operational technology or communication networks. However, the lack of remote exploitability and no requirement for user interaction somewhat limits the attack surface, reducing the likelihood of widespread exploitation without physical or local access.

To mitigate CVE-2025-21433, organizations should implement a multi-layered approach beyond generic patching advice. First, identify all devices and systems utilizing affected Qualcomm Snapdragon platforms through asset inventory and hardware/software audits. Since no official patches or updates are currently linked, monitor Qualcomm and device vendor advisories closely for forthcoming firmware or software updates addressing this vulnerability. In the interim, restrict local access to critical devices by enforcing strict physical security controls and limiting administrative privileges to trusted personnel only. Implement application whitelisting and input validation controls on systems that handle RSA private keys to detect and block malformed or suspicious key imports. For environments where importing RSA keys is necessary, enforce strict validation of key formats and sizes at the application or middleware level to prevent malformed keys from reaching vulnerable components. Employ endpoint detection and response (EDR) solutions to monitor for abnormal crashes or denial of service symptoms indicative of exploitation attempts. Additionally, educate staff on secure key management practices to avoid accidental introduction of malformed keys. For embedded or IoT devices, consider network segmentation to isolate vulnerable devices from critical infrastructure, minimizing potential impact. Finally, prepare incident response plans that include procedures for handling denial of service events related to this vulnerability.