CVE-2020-10810 in HDF5
Summary
by MITRE
An issue was discovered in HDF5 through 1.12.0. A NULL pointer dereference exists in the function H5AC_unpin_entry() located in H5AC.c. It allows an attacker to cause Denial of Service.
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Analysis
by VulDB Data Team • 05/11/2025
The vulnerability identified as CVE-2020-10810 represents a critical null pointer dereference flaw within the Hierarchical Data Format version 5 library, specifically affecting versions through 1.12.0. This issue manifests within the H5AC_unpin_entry() function located in the H5AC.c source file, where improper validation of pointer references leads to system instability. The flaw arises from insufficient input validation mechanisms that fail to properly handle cases where memory references may become null during the cache entry unpinning process, creating a predictable crash condition that can be exploited by malicious actors.
The technical exploitation of this vulnerability occurs when an attacker crafts specially malformed HDF5 files or data structures that trigger the specific code path leading to the null pointer dereference. When the H5AC_unpin_entry() function executes with invalid memory references, the application crashes immediately due to the operating system's handling of the null pointer access violation. This behavior constitutes a denial of service condition that can be reliably triggered by any process attempting to interact with the vulnerable HDF5 library, making it particularly dangerous in environments where continuous operation is critical. The vulnerability maps directly to CWE-476 which describes NULL pointer dereference conditions in software systems.
From an operational impact perspective, this vulnerability creates significant risks for systems that rely on HDF5 for data storage and processing, including scientific computing environments, data analysis platforms, and applications handling large datasets. The denial of service condition can be exploited remotely through file upload mechanisms or by processing maliciously crafted data streams, potentially leading to complete system unavailability. Attackers can leverage this vulnerability to disrupt services in high-availability environments, making it particularly attractive for persistent threat actors seeking to maintain system instability. The flaw aligns with ATT&CK technique T1499.004 which covers network denial of service attacks through application-level exploits.
Mitigation strategies for CVE-2020-10810 should prioritize immediate patching of affected systems with the latest HDF5 releases that contain the necessary code fixes. Organizations should implement strict file validation controls for all HDF5 data processing pipelines, including input sanitization and format verification mechanisms that can detect and reject malformed data before it reaches the vulnerable code path. Network segmentation and access controls should be strengthened to limit exposure of systems handling HDF5 data to untrusted sources. Additionally, monitoring systems should be configured to detect unusual crash patterns or service disruptions that may indicate exploitation attempts. Security teams should conduct comprehensive vulnerability assessments across all systems utilizing HDF5 libraries to identify and remediate similar issues that may exist in other software components. The fix typically involves implementing proper null pointer checks and ensuring that all memory references are validated before access, preventing the execution path that leads to the denial of service condition.