CVE-2025-59729

/// Technical description

When parsing the header for a DHAV file, there's an integer underflow in offset calculation that leads to reading the duration from before the start of the allocated buffer.

If we load a DHAV file that is larger than MAX_DURATION_BUFFER_SIZE bytes (0x100000) for example 0x101000 bytes, then at [0] we have size = 0x101000. At [1] we have end_buffer_size = 0x100000, and at [2] we have end_buffer_pos = 0x1000.

The loop then scans backwards through the buffer looking for the dhav tag; when it is found, we'll calculate end_pos based on a 32-bit offset read from the buffer.

There is subsequently a check [3] that end_pos is within the section of the file that has been copied into end_buffer, but it only correctly handles the cases where end_pos is before the start of the file or after the section copied into end_buffer, and not the case where end_pos is within the the file, but before the section copied into end_buffer. If we provide such an offset, (end_pos - end_buffer_pos) can underflow

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References