CVE-2020-10809 in HDF5
Summary
by MITRE
An issue was discovered in HDF5 through 1.12.0. A heap-based buffer overflow exists in the function Decompress() located in decompress.c. It can be triggered by sending a crafted file to the gif2h5 binary. 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-2020-10809 represents a critical heap-based buffer overflow within the HDF5 library version 1.12.0 and earlier. This flaw resides in the Decompress() function within the decompress.c source file, making it a significant security concern for systems that process HDF5 formatted data. The vulnerability specifically affects the gif2h5 binary which serves as a utility for converting gif image files into HDF5 format, creating an attack surface where maliciously crafted input files can trigger the overflow condition.
The technical nature of this vulnerability stems from inadequate bounds checking within the Decompress() function, which processes compressed data streams during the conversion process. When the gif2h5 utility encounters a specially crafted gif file containing malformed compression data, the decompression routine fails to properly validate buffer boundaries before writing decompressed data into allocated memory regions. This failure creates a condition where the program writes beyond the allocated buffer space, potentially overwriting adjacent memory locations and corrupting program execution flow. The vulnerability is classified as a heap-based buffer overflow under CWE-121, which specifically addresses buffer overflow conditions occurring in heap memory allocations.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides attackers with the capability to cause system instability and potentially execute arbitrary code. While the immediate effect manifests as denial of service through application crashes or system resource exhaustion, the underlying memory corruption could enable more sophisticated attacks if exploited properly. The vulnerability affects systems that process user-supplied gif files through the gif2h5 utility, making it particularly concerning for web applications, file processing services, and any environment where untrusted input files are converted to HDF5 format. This represents a significant risk in environments where automated file conversion processes are employed, as attackers could craft malicious gif files to disrupt services continuously.
Mitigation strategies for CVE-2020-10809 should prioritize immediate patching of affected HDF5 library versions to 1.12.1 or later, where the buffer overflow has been addressed through proper bounds checking implementation. Organizations should implement input validation measures for all file conversion processes, particularly those involving the gif2h5 utility, by employing strict file format validation and size limitations before processing. Network segmentation and access controls should be implemented to limit exposure of systems running the gif2h5 utility to untrusted input sources. Additionally, monitoring systems should be configured to detect abnormal resource consumption patterns or application crashes that could indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1203, which covers exploitation of software vulnerabilities for privilege escalation and denial of service, making it essential for security teams to monitor and remediate this issue across all affected systems.