CVE-2025-44905 is a high-severity heap buffer overflow vulnerability identified in the HDF5 library version 1.14.6. The flaw exists within the H5Z__filter_scaleoffset function, which is responsible for applying the scale-offset filter during data compression or decompression operations in HDF5 files. A heap buffer overflow occurs when the function improperly handles memory allocation or indexing, allowing an attacker to overwrite adjacent memory on the heap. This can lead to arbitrary code execution, data corruption, or application crashes. The vulnerability is exploitable remotely without requiring privileges (AV:N/AC:L/PR:N), but it does require user interaction (UI:R), such as opening or processing a maliciously crafted HDF5 file. The scope is unchanged (S:U), meaning the impact is limited to the vulnerable component and does not extend to other system components. The CVSS v3.1 base score is 8.8, reflecting high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits are currently reported in the wild, and no vendor patches or mitigations have been linked yet. The vulnerability is classified under CWE-122 (Heap-based Buffer Overflow), a common and dangerous memory corruption issue. HDF5 is widely used in scientific computing, data analysis, and engineering fields for managing large and complex datasets, making this vulnerability particularly relevant for organizations processing such data.

For European organizations, the impact of CVE-2025-44905 can be significant, especially those involved in research institutions, universities, scientific computing centers, and industries relying on large-scale data storage and analysis such as aerospace, automotive, pharmaceuticals, and energy sectors. Exploitation could lead to unauthorized code execution, potentially allowing attackers to gain control over critical systems, steal sensitive research data, or disrupt operations. The vulnerability could also be leveraged as an entry point for lateral movement within networks. Since HDF5 files are often shared and processed across collaborative projects, malicious files could be introduced via email attachments, shared drives, or data repositories, increasing the risk of infection. The requirement for user interaction means social engineering or phishing campaigns could be used to trick users into opening malicious files. The absence of patches increases the window of exposure. Additionally, disruption of data integrity and availability could impact compliance with data protection regulations such as GDPR, especially if personal or sensitive data is involved.

European organizations should implement several targeted mitigations: 1) Restrict and monitor the handling of HDF5 files, especially from untrusted sources. Implement strict file validation and sandboxing when processing these files. 2) Educate users about the risks of opening unsolicited or unexpected HDF5 files and train them to recognize phishing attempts. 3) Employ application whitelisting and endpoint protection solutions capable of detecting anomalous behavior related to heap overflows or exploitation attempts. 4) Use network-level controls to monitor and block suspicious file transfers or communications involving HDF5 data. 5) Maintain up-to-date backups of critical datasets to enable recovery in case of data corruption or ransomware triggered by exploitation. 6) Engage with HDF5 library maintainers and monitor security advisories for patches or updates, and plan for rapid deployment once available. 7) Consider deploying runtime application self-protection (RASP) or memory protection technologies such as Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to reduce exploitation success rates. 8) Conduct regular vulnerability assessments and penetration testing focusing on data processing pipelines that utilize HDF5.