CVE-2025-53183 is a heap-based buffer overflow vulnerability identified in the PDF preview module of Huawei's HarmonyOS versions 5.0.1 and 5.1.0. The vulnerability is classified under CWE-122, which pertains to improper memory handling leading to buffer overflows on the heap. Specifically, the issue involves a null pointer dereference within the PDF preview functionality. When a specially crafted PDF file is processed by the vulnerable module, it may trigger a heap overflow condition. This can cause the application or system function responsible for rendering PDF previews to become unstable or crash, impacting the availability of the affected service. The CVSS v3.1 base score is 6.5, indicating a medium severity level. The vector string (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H) reveals that the attack can be executed remotely over the network without privileges but requires user interaction (e.g., opening a malicious PDF). The vulnerability does not compromise confidentiality or integrity but results in a denial of service due to loss of availability. No known exploits are currently reported in the wild, and no patches have been published yet. The vulnerability was reserved on June 27, 2025, and published on July 7, 2025. Given the nature of the flaw, it primarily affects the stability of the PDF preview feature within HarmonyOS and could be leveraged by attackers to disrupt normal device operations or cause application crashes, potentially leading to denial of service conditions on affected devices.

For European organizations, the impact of CVE-2025-53183 depends largely on the adoption rate of Huawei HarmonyOS devices within their operational environment. Organizations using HarmonyOS-powered devices, especially those that rely on PDF document handling or previewing capabilities on these devices, may experience service disruptions due to crashes or instability triggered by maliciously crafted PDFs. This could affect productivity, particularly in sectors where document exchange and review are frequent, such as legal, finance, and government agencies. Although the vulnerability does not lead to data breaches or unauthorized access, denial of service conditions could interrupt workflows and cause operational delays. Additionally, if HarmonyOS devices are integrated into critical infrastructure or used in industrial control systems, the availability impact could have broader consequences. The requirement for user interaction means that social engineering or phishing campaigns could be used to deliver malicious PDFs, increasing the risk of exploitation in environments with less stringent user awareness training. However, the absence of known exploits in the wild and the medium severity rating suggest that the immediate risk is moderate but should not be ignored.

To mitigate the risk posed by CVE-2025-53183, European organizations should implement several targeted measures beyond generic advice: 1) Restrict or monitor the use of Huawei HarmonyOS devices within sensitive or critical environments until patches are available. 2) Educate users about the risks of opening unsolicited or unexpected PDF files, especially from untrusted sources, to reduce the likelihood of triggering the vulnerability. 3) Employ network-level protections such as email filtering and sandboxing to detect and block malicious PDF attachments before they reach end users. 4) Implement application whitelisting or sandboxing on HarmonyOS devices to limit the impact of crashes and prevent cascading failures. 5) Monitor device logs and system stability indicators for signs of crashes or abnormal behavior related to PDF preview operations. 6) Engage with Huawei or authorized vendors to obtain timely patches or updates once they are released and prioritize their deployment. 7) Consider alternative document preview solutions or workflows that do not rely on the vulnerable module until the issue is resolved. These steps will help reduce the attack surface and mitigate potential denial of service impacts caused by this vulnerability.