CVE-2025-21421 is a buffer over-read vulnerability classified under CWE-126, discovered in Qualcomm Snapdragon platforms and associated wireless connectivity components. The vulnerability stems from improper handling of escape codes within a specific API, causing memory corruption. This flaw can be triggered by a local attacker with limited privileges (PR:L) without requiring user interaction (UI:N). The vulnerability affects a broad range of Qualcomm products, including multiple Snapdragon compute platforms (e.g., 7c, 8c, 8cx series), FastConnect wireless modules (6200 through 7800 series), and various WCD and WSA audio components. The memory corruption could allow an attacker to read beyond intended memory boundaries, potentially exposing sensitive information, modifying critical data, or causing denial of service. The CVSS v3.1 base score is 7.8, indicating high severity, with impacts rated high on confidentiality, integrity, and availability. Although no public exploits are currently known, the extensive deployment of affected hardware in smartphones, laptops, and IoT devices worldwide makes this vulnerability a significant concern. The lack of available patches at the time of disclosure necessitates immediate risk mitigation through access restrictions and monitoring. Qualcomm’s broad product portfolio and market penetration mean that this vulnerability could be leveraged in targeted attacks or privilege escalation scenarios on compromised devices.

The vulnerability poses a serious risk to organizations and end-users relying on affected Qualcomm Snapdragon platforms and wireless modules. Successful exploitation can lead to unauthorized disclosure of sensitive data, unauthorized modification of system or application memory, and denial of service conditions, potentially resulting in device crashes or instability. Given the widespread use of Snapdragon SoCs in mobile phones, laptops, and IoT devices, the impact spans multiple industries including telecommunications, consumer electronics, enterprise computing, and critical infrastructure. Attackers with local access could leverage this flaw to escalate privileges, bypass security controls, or extract confidential information, undermining device security and user privacy. The broad range of affected hardware increases the attack surface, and the absence of required user interaction facilitates stealthy exploitation. This vulnerability could also be a stepping stone for more complex multi-stage attacks, particularly in environments where devices are shared or exposed to untrusted users. The global scale of Snapdragon deployments means that organizations worldwide must consider this vulnerability in their risk assessments and incident response planning.

Until official patches are released by Qualcomm, organizations should implement strict local access controls to limit the ability of unprivileged users to interact with vulnerable APIs. Employing endpoint protection solutions that monitor for anomalous memory access patterns or suspicious API usage can help detect exploitation attempts. Device administrators should audit and restrict software installations and execution privileges to minimize the risk of local attackers gaining footholds. Network segmentation and device hardening can reduce exposure, especially in enterprise environments. Once Qualcomm releases patches or firmware updates, organizations must prioritize timely deployment across all affected devices. Additionally, monitoring vendor advisories and threat intelligence feeds for emerging exploit techniques related to this vulnerability is critical. For mobile devices, users should be encouraged to update their operating systems and firmware promptly. In environments where patching is delayed, consider disabling or restricting the vulnerable API if feasible. Finally, conducting regular security assessments and penetration tests focusing on local privilege escalation vectors can help identify and remediate exploitation paths related to this vulnerability.