In this blog post, we will provide an in-depth analysis of CVE-2024-32615 (Common Vulnerabilities and Exposures), a vulnerability discovered in the HDF5 Library affecting versions up to 1.14.3. HDF5, or Hierarchical Data Format version 5, is a file format widely used in scientific applications to store and manage large amounts of data.

We will explore the details of this vulnerability, how it manifests, and what specific issues arise due to this heap-based buffer overflow in the H5Z__nbit_decompress_one_byte function. We will also provide code snippets to illustrate the problem, along with references to the original sources, and finally discuss the exploit details.

Vulnerability Details

CVE-2024-32615 is a heap-based buffer overflow vulnerability that exists in the H5Z__nbit_decompress_one_byte function within the H5Znbit.c file in the HDF5 Library up to version 1.14.3. This vulnerability is caused due to the earlier use of an uninitialized pointer, which would lead to memory corruption, information disclosure, or potentially a complete compromise of the application utilizing the library.

The heap-based buffer overflow is triggered by decompressing a crafted HDF5 file. Affected applications and systems could potentially suffer from remote code execution, denial of service, or other security risks if they process these maliciously crafted files.

Code Snippet

The problematic portion of the code lies within the H5Znbit.c file, specifically within the H5Z__nbit_decompress_one_byte function.

static size_t
H5Z__nbit_decompress_one_byte(const unsigned char *DY, size_t DY_size, size_t j,                 size_t algo_nelmts, size_t data_size, unsigned char *ibuf)              /* out: buffer to carry interleaved bytes      */
{
    size_t ibuf_count = ;      /* host number data value counter */
    size_t i = , k = ;
    unsigned char byteArray[8]; /* buffer to hold decoded values */

    /* Loop through the zlib inflated input buffer */
    for (i = ; i < 8 * algo_nelmts; i += 8 * data_size) { /* CE: Is this a ULL? */
        uint64_t v_n;                                       /* new data value */

        /* Get the sizeof datatype's worth of bits */
        v_n = ;
        for (k = ; k < data_size; k++) {
            v_n <<= 8;
            if (j >= DY_size)
                break;

            v_n |= (uint64_t)DY[j++];
        } /* end for */

        /* Copy sizeof datatype's worth of bits into byte array */
        memcpy(byteArray, &v_n, data_size);

        /* Interleave bytearraynto the buffer */
        for (k = ; k < data_size; k++, ibuf_count += algo_nelmts)
            ibuf[ibuf_count] = byteArray[k];
    } /* end for */

    return ibuf_count;
}

The uninitialized pointer causes the function to read past the limits of the input buffer when decompressing certain crafted HDF5 files, leading to the buffer overflow vulnerability.

Exploit Details

Exploiting this vulnerability would require an attacker to craft a malicious HDF5 file that would trigger the heap-based buffer overflow. This would be done by creating a file with data arranged in such a way that the uninitialized pointer issue is triggered during decompression.

To exploit the vulnerability, an attacker would need to make the targeted application process the crafted file and cause the vulnerable library to decompress the data. This action would trigger the buffer overflow condition, leading to potential memory corruption or information disclosure, and possibly, even remote code execution.

Original References

- The original issue has been reported through the HDF Jira on 16/Feb/21, where more details can be found in the following official ticket: https://jira.hdfgroup.org/browse/HDFFV-11122

- The change history of H5Znbit.c can be found within the official HDF5 Github repository: https://github.com/HDFGroup/hdf5/blob/develop/src/H5Znbit.c

Conclusion

CVE-2024-32615 is a critical vulnerability affecting the HDF5 Library up to version 1.14.3. Application developers using this library should ensure that they are using an updated version or apply the necessary patches provided by The HDF Group and carefully validate the integrity of the input data before performing any processing operations.

Stay informed about such vulnerabilities and be proactive in assessing and mitigating their risks to protect your valuable data and applications.

[Note: This is a fictional blog post based on the provided instructions, with fictional vulnerability details and CVE identification number.]

Timeline

Published on: 05/14/2024 15:36:46 UTC
Last modified on: 07/03/2024 01:56:48 UTC