CVE-2025-44904 HDF5 Heap Buffer Overflow in H5VM_memcpyvv Function

CVE-2025-44904 identifies a critical heap buffer overflow vulnerability affecting HDF5 library version 1.14.6, specifically within the H5VM_memcpyvv function. The HDF5 (Hierarchical Data Format) library is widely used for storing and managing large data sets. This flaw could enable an attacker to corrupt memory or execute arbitrary code by providing specially crafted HDF5 data to an application that uses the vulnerable library. While the Microsoft Security Response Center (MSRC) has disclosed the vulnerability, details regarding active exploitation or specific attack campaigns are not yet public. The potential for arbitrary code execution makes this a significant concern for organizations utilizing HDF5 v1.14.6 in their applications, as it could compromise data integrity, system availability, or lead to full system compromise.

Attack Chain

1. An attacker crafts a malicious HDF5 file or data stream designed to trigger the heap buffer overflow vulnerability.
2. The malicious HDF5 data is delivered to a target system or application that processes HDF5 files using the vulnerable HDF5 library v1.14.6.
3. The application attempts to parse or process the malformed HDF5 data, leading to a call to the H5VM_memcpyvv function.
4. During the execution of H5VM_memcpyvv, the crafted input causes an out-of-bounds write operation, overflowing a heap buffer.
5. This overflow corrupts adjacent memory regions, potentially overwriting critical data structures or control flow pointers.
6. Depending on the exact memory layout and the attacker's control over the overwritten data, this could lead to a denial of service (application crash) or arbitrary code execution within the context of the vulnerable application.

Impact

A successful exploitation of CVE-2025-44904 could result in severe consequences for applications relying on the HDF5 library v1.14.6. The primary impacts include denial of service, causing applications to crash and become unavailable, or data corruption due to arbitrary memory modification. In more sophisticated attacks, it could enable arbitrary code execution, allowing an attacker to run malicious code with the same privileges as the compromised application. This could lead to further system compromise, data exfiltration, or complete control over the affected system, depending on the application's privileges and environment.

Recommendation

• Prioritize patching of HDF5 library to a non-vulnerable version as soon as a fix is available, specifically for applications using hdf5 (v1.14.6).
• Monitor the MSRC reference for updates on patches or mitigation strategies for CVE-2025-44904.
• Implement robust input validation for all HDF5 files processed by applications to detect and reject malformed data before it reaches the H5VM_memcpyvv function.