CVE-2025-66332 is a vulnerability identified in Huawei's HarmonyOS, specifically within the office service component. The root cause is the download of code without performing integrity checks, classified under CWE-494. This flaw allows an attacker to cause a denial of service (DoS) condition by potentially introducing malformed or malicious code that disrupts the normal operation of the office service, thereby affecting system availability. The vulnerability affects HarmonyOS versions 5.0.1, 5.1.0, and 6.0.0. According to the CVSS 3.1 vector (3.3 base score), exploitation requires local access (AV:L), low attack complexity (AC:L), no privileges (PR:N), and user interaction (UI:R). The scope is unchanged (S:U), and the impact is limited to availability (A:L) without affecting confidentiality or integrity. No known exploits have been reported in the wild, and no patches have been published yet. The vulnerability's exploitation could lead to temporary denial of service conditions in devices running the affected HarmonyOS versions, potentially disrupting business operations relying on these systems. The lack of integrity checks during code download is a critical security oversight that could be leveraged by attackers with local access to destabilize the system.

For European organizations, the primary impact is on availability, potentially causing denial of service in devices running the affected HarmonyOS versions. This could disrupt business continuity, especially in environments where Huawei devices are integrated into critical workflows or communication systems. Although the severity is low, repeated or targeted exploitation could degrade user productivity and operational reliability. The requirement for local access and user interaction limits the attack surface, reducing risk for remote or external attackers. However, insider threats or malware that gains local access could exploit this vulnerability. Sectors such as telecommunications, manufacturing, and public services that utilize Huawei hardware and HarmonyOS may experience service interruptions. The absence of confidentiality or integrity impact reduces risks related to data breaches or manipulation but does not eliminate operational risks. Organizations relying on Huawei's ecosystem should monitor for unusual office service behavior and prepare for patch deployment once available.

1. Restrict local access to devices running affected HarmonyOS versions by enforcing strict physical and logical access controls. 2. Educate users to avoid interacting with untrusted or suspicious office service prompts that could trigger the vulnerability. 3. Implement endpoint monitoring to detect anomalous behavior or crashes related to the office service. 4. Use application whitelisting and integrity verification tools where possible to detect unauthorized code downloads or modifications. 5. Maintain up-to-date backups and incident response plans to quickly recover from potential denial of service events. 6. Engage with Huawei support channels to obtain patches or workarounds as they become available and prioritize timely deployment. 7. Limit installation of unverified third-party applications that could exploit this vulnerability to trigger DoS conditions. 8. Consider network segmentation to isolate critical HarmonyOS devices and reduce the risk of lateral movement by attackers with local access.