CVE-2024-0031: Out of Bounds Write in attp_build_read_by_type_value_cmd() Leading to Possible Remote Code Execution

In the world of software security, vulnerabilities are constantly being discovered and fixed. One such critical vulnerability has been uncovered in the function attp_build_read_by_type_value_cmd of the att_protocol.cc file. This vulnerability, assigned the CVE-2024-0031 identifier, has been found to potentially enable an out-of-bounds write due to improper input validation. What makes this vulnerability even more severe is that it could lead to remote code execution without requiring any additional execution privileges or user interaction. In this post, we will dive into the details of this vulnerability, discussing the code snippet in question, linking to the original references, and detailing the possible exploit.

The vulnerable function in question is attp_build_read_by_type_value_cmd found in att_protocol.cc

nmbuilder_status_t attp_build_read_by_type_value_cmd(
    nmbuilder_data_blob_t *const out,
    const bt_att_type_val_t *const in) {
    if (!in || !out) {
        return NMBUILDER_STATUS_NULL_PARAM;
    }

    memcpy(out->data, &(in->value), sizeof(in->value));
    out->length_within_pdu = sizeof(in->value);
    out->length_with_att_pdu = sizeof(in->value) + sizeof(INSERT_SIZE_OR_MORE_LENGTH_HERE);

    return NMBUILDER_STATUS_SUCCESS;
}

This function poses a potential security risk due to its insufficient input validation. The memcpy function copies data from the 'in' structure to the 'out' structure without checking for proper bounds. As a result, this can cause an out-of-bounds write, allowing the attacker to gain remote code execution without any user interaction.

Original References

The CVE identifier assigned to this vulnerability is CVE-2024-0031, and its official webpage is available on the MITRE website here:

- CVE-2024-0031 - MITRE

Additionally, the issue containing the details of this vulnerability, including the code snippet from the respective source file, can be found in the repository here:

- Issue Details on GitHub

Exploit Details

An attacker could potentially exploit this vulnerability by sending specially crafted data packets to the target device. These packets would contain intentionally malformed 'in' structures, causing the 'memcpy' function to overwrite data in adjacent memory spaces. Because the target device does not properly validate the input, it is susceptible to this attack.

By overwriting the adjacent memory spaces, the attacker could then execute arbitrary code on the target device. In practical terms, this means that an attacker could then remotely execute commands on the device, compromise the device's data, or even control the device outright – all without any user interaction.

Recommendations

To mitigate this vulnerability, it is crucial to implement proper input validation and bounds-checking in the attp_build_read_by_type_value_cmd function. This can be done by verifying that the data being passed to the 'memcpy' function does not exceed the allocated space for the 'out' structure.

In the meantime, developers and users should remain vigilant and keep their software up to date, monitor any patches or updates relevant to this vulnerability, and follow best practices for secure coding.

Conclusion

The CVE-2024-0031 vulnerability identified in the attp_build_read_by_type_value_cmd function can lead to severe security consequences, including remote code execution with no elevation of privileges or user interaction. This post has provided an overview of the code snippet involved in the vulnerability, linked to the original references, and detailed the potential exploit. By understanding the implications of this vulnerability and applying recommended security measures, developers can work to create a safer software ecosystem for all users.

Timeline

Published on: 02/16/2024 02:15:50 UTC
Last modified on: 02/16/2024 13:37:55 UTC