CVE-2025-31719 identifies a vulnerability in the Trusted Execution Environment (TEE) implementation of the Elliptic Curve Digital Signature Algorithm (EcDSA) on Unisoc (Shanghai) Technologies Co., Ltd. chipsets, including models SC7731E, SC9832E, SC9863A, and multiple T-series variants. The issue stems from improper initialization leading to a memory consistency problem within the TEE's cryptographic operations. This flaw can cause the generation of incorrect digital signatures, albeit with a low probability. Since EcDSA signatures are critical for ensuring data integrity and authentication, incorrect signatures can undermine trust in cryptographic processes. The vulnerability affects devices running Android versions 13 through 16 that incorporate these Unisoc chipsets. The CVSS v3.1 score is 5.1 (medium), reflecting that the attack vector is local (AV:L), with low complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N). The impact is limited to integrity and availability, with no confidentiality loss. No patches are currently linked, and no exploits have been reported in the wild. The CWE classification is CWE-665, indicating improper initialization as the root cause. This vulnerability highlights risks in secure hardware-based cryptographic implementations, especially in resource-constrained or budget mobile devices where Unisoc chipsets are prevalent.

For European organizations, the primary impact lies in the potential compromise of cryptographic integrity on devices using affected Unisoc chipsets. This could affect secure communications, authentication mechanisms, and digital signature validation processes relying on the TEE EcDSA implementation. Although the probability of incorrect signature generation is low, such errors could lead to denial of service in security-critical applications or undermine trust in device-generated signatures. The vulnerability does not expose confidential data directly but may disrupt availability and integrity of cryptographic functions. Organizations relying on mobile devices with these chipsets for secure access or sensitive operations may face increased risk of operational disruptions or security policy violations. The local attack vector and lack of required privileges reduce the likelihood of widespread remote exploitation but insider threats or compromised devices could exploit this flaw. The absence of known exploits currently limits immediate risk but proactive mitigation is advised.

Organizations should monitor Unisoc and device vendor advisories for patches addressing this vulnerability and apply updates promptly once available. In the interim, restrict physical and local access to devices with affected chipsets to trusted personnel only. Employ device management solutions to inventory and identify devices running vulnerable Unisoc chipsets and Android versions 13 to 16. Where feasible, consider replacing or isolating devices that cannot be patched. Implement additional layers of cryptographic verification outside the TEE when possible, such as server-side signature validation or multi-factor authentication, to mitigate risks from incorrect signatures. Educate users and administrators about the potential risks of local exploitation and enforce strict access controls. Regularly audit cryptographic operations and logs for anomalies that may indicate signature failures or tampering attempts. Collaborate with mobile device manufacturers and Unisoc for timely security updates and guidance.