The Hierarchical Data Format version 5 (HDF5) is a popular data model, library, and file format for efficiently storing and managing large amounts of data, as well as providing the ability to access, process, and visualize data. The HDF5 software suite can be used on a wide range of platforms and environments, making it an essential component in data-intensive applications. However, with the presence of vulnerabilities in the codebase, the integrity of the system and data are at serious risk.

Recently, a new stack buffer overflow vulnerability, assigned as CVE-2024-29164, has been discovered in the HDF5 library, affecting versions up to 1.14.3. This post will provide an in-depth analysis of the vulnerability, including a code snippet, links to original references, and exploit details. We will be using simple American language in order to make the content accessible to a wide audience.

Understanding the Vulnerability

In the affected versions of HDF5, a stack buffer overflow is present, causing a corruption of the instruction pointer, which results in denial of service (DoS) or potential code execution. This vulnerability has been found in the H5R__decode_heap function of the library. A stack buffer overflow occurs when the program writes to a memory location beyond the boundaries of a buffer, potentially corrupting other memory locations and leading to unpredictable behavior.

In the following lines, we will examine the vulnerable function and the conditions that led to the buffer overflow.

The Vulnerable Function: H5R__decode_heap

The H5R__decode_heap function is responsible for decoding binary heap data in the H5R.obj_t struct. Here is the code snippet containing the vulnerable part:

ssize_t
H5R__decode_heap(H5F_t *f, uint8_t **_pp, H5R.obj_t *obj)
{
    uint8_t *pp = *_pp;          /* Pointer to the object in the heap */
    ssize_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Check args */
    HDassert(f); /* Check the file */
    HDassert(obj.ptr.oid); /* Check the binary heap pointer */
    HDassert(obj.ptr.oid[]);

    obj.heap_loc.offset = *pp++; /* Set offset from pointer */
    obj.ptr.oid_len = *pp++; /* Set OID length */
    HDstrncpy(obj.ptr.oid, (const char *)pp, H5R_MAX_OID_LEN); /* BUG_HERE: Stack Buffer Overflow  */

    /* Set pointer to the heap */
    obj.heap_id = obj.heap_did = HADDR_UNDEF;

    FUNC_LEAVE_NOAPI(ret_value)
}

The vulnerability occurs at the line containing HDstrncpy, which is the call that leads to a buffer overflow. This happens because of the lack of proper boundary checks on the copy operation, which allows a malicious payload to overwrite adjacent memory locations when obj.ptr.oid_len exceeds H5R_MAX_OID_LEN.

Exploit Details

The stack buffer overflow can be triggered by manipulating the binary heap data in such a way that obj.ptr.oid_len is set to an incorrect or malicious value. This, in turn, can lead to the corruption of adjacent memory locations, including the instruction pointer, which eventually results in denial of service or potential code execution.

Exploiting this vulnerability can be achieved by crafting a malformed HDF5 file containing intentionally manipulated binary heap data, which, when processed by an application utilizing the HDF5 library, will trigger the vulnerability.

- HDF5 Advisory

Moreover, you can access an in-depth technical analysis of the vulnerability, along with a proof-of-concept file and additional exploit details in the following reference:

- CVE-2024-29164 - Stack Buffer Overflow in HDF5

Mitigation and Recommendations

Users and developers using the HDF5 library are strongly advised to update their library to the latest version. The HDF Group has released a patch to address this vulnerability in version 1.15., which can be downloaded from their official website:

- Download HDF5 1.15.

Additionally, until you can update your library, it is highly recommended that you take extra precautions when handling HDF5 files from untrusted sources. Always validate user inputs, sanitize them, and consider implementing proper bounds checking to prevent buffer overflows.

Timeline

Published on: 05/14/2024 15:15:33 UTC
Last modified on: 07/03/2024 01:52:13 UTC