CVE-2025-6856
BaseFortify
Publication date: 2025-06-29
Last updated on: 2026-04-29
Assigner: VulDB
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| hdfgroup | hdf5 | 1.14.6 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-119 | The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. |
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2025-6856 is a use-after-free vulnerability in the HDF5 library version 1.14.6, specifically in the function H5FL__reg_gc_list in the source file src/H5FL.c. This flaw occurs when the program accesses memory that has already been freed, leading to undefined behavior such as program crashes or potential denial of service. The vulnerability was discovered through fuzz testing and involves improper handling of heap memory during the library's termination sequence. Exploitation requires local access, and a proof-of-concept exploit is publicly available. [1, 2, 3]
How can this vulnerability impact me? :
This vulnerability can cause the affected software to crash or behave unexpectedly due to accessing freed memory, leading to a denial of service (DoS) condition. While it does not impact confidentiality or integrity, it affects the availability of the software. Exploitation requires local access, and the exploit is considered easy to perform. There are no known mitigations, so affected users should consider replacing the vulnerable component. [1, 3]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability is a local use-after-free in the HDF5 library and is not detectable via network monitoring. Detection can be performed by running the HDF5 library or applications using it with AddressSanitizer enabled to catch heap-use-after-free errors. Using fuzz testing tools like OSS-Fuzz's h5_extended_fuzzer.c can help trigger the issue. For example, compiling the HDF5 library with AddressSanitizer and running tests that open files (e.g., using H5Fopen) can reveal the vulnerability. Specific commands include compiling with Clang and AddressSanitizer flags (e.g., clang -fsanitize=address) and running the fuzzing harness or test programs that exercise HDF5 file operations. [2]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restricting local access to systems running the vulnerable HDF5 version 1.14.6, as exploitation requires local access. Since no known countermeasures or patches are currently available, consider replacing or upgrading the affected HDF5 component to a non-vulnerable version once available. Monitoring for updates from the HDFGroup and applying patches promptly is advised. Additionally, avoid running untrusted code or inputs that use the vulnerable HDF5 library to reduce risk. [1]