Exploring CVE-2024-32620 - Heap-Based Buffer Over-Read Vulnerability in HDF5 Library

Cybersecurity has become one of the critical concerns for developers, as hackers have intensified their attacks on various vulnerable software systems. Keeping applications up to date and patching vulnerabilities are the first steps to maintain a secure system. In this article, we will explore CVE-2024-32620, a critical vulnerability present in the HDF5 Library until version 1.14.3. This vulnerability permits a heap-based buffer over-read in the H5F_addr_decode_len function, resulting in the corruption of the instruction pointer.

Vulnerability Details

CVE-2024-32620 is a vulnerability that exists in the HDF5 Library (Hierarchical Data Format) through 1.14.3. This library is broadly employed in data storage and management systems, which makes this vulnerability particularly concerning.

The problem resides in a heap-based buffer over-read within the H5F_addr_decode_len function in H5Fint.c. The buffer over-read causes corruption of the instruction pointer, which could lead to the possibility of code execution, denial-of-service (DoS), or the disclosure of sensitive information.

Exploit

We will now discuss the specifics of the vulnerability. In the following code snippet from H5Fint.c, we can observe where the vulnerability occurs:

/* H5Fint.c */

...

/* Decode encoded size of address */
static H5F_addr_decode_len(uint8_t **pp, uint8_t* p_end, haddr_t *addr_ptr, unsigned enc_addr_size)
{
    /* Sanity checks */
    assert(pp && *pp);
    assert(addr_ptr);
    assert(enc_addr_size);

    /* Check buffer overrun prevention */
    if (p_end - *pp < (ptrdiff_t)enc_addr_size)
    {
        return FALSE;
    }

    /* Decode the address of the requested size */
    while(enc_addr_size--)
    {
        *addr_ptr = (*addr_ptr << 8) | *(*pp)++;
    }

    return TRUE;
}

...

In the above code snippet, the function H5F_addr_decode_len accepts a uint8_t double pointer (pp), ending position pointer (p_end), address pointer (addr_ptr), and the encoded address length (enc_addr_size). The "Sanity checks" verify that these pointers are non-null, and enc_addr_size is a valid positive integer.

However, when the function checks for buffer overrun prevention, it doesn’t sufficiently validate and constrain the size. Consequently, if an attacker could alter the enc_addr_size to a size larger than intended, they might be able to provoke a heap-based buffer over-read, corrupting the instruction pointer.

Mitigation

The HDF Group, responsible for maintaining the HDF5 Library, has issued a new release (1.14.4) to address this vulnerability. It is highly advised that users and applications leveraging the HDF5 Library update to the latest version to secure their systems and data from potential exploits that might use the vulnerability.

Original References

1. HDF5 Library Official Website
2. HDF5 Library 1.14.4 Release Notes with Security Fix
3. CVE-2024-32620 Vulnerability Details

Conclusion

CVE-2024-32620 demonstrates that even widely used data storage libraries like HDF5 are vulnerable to exploitation. It is imperative for developers and system administrators to keep an eye on changes and updates for the software they employ in their infrastructure, ensuring that they stay protected against known vulnerabilities. Ensuring systems are up to date will minimize the risk of attackers exploiting instances like the heap-based buffer over-read and corrupting the instruction pointer as observed in this vulnerability.

Timeline

Published on: 05/14/2024 15:36:47 UTC
Last modified on: 07/03/2024 01:56:51 UTC