The vulnerability occurs in the render_bin_output function of the h5dump tool in HDF5 versions before 2.1.1. When dumping a variable-length string dataset containing more than one element in binary mode, the stride calculation for each element becomes corrupted. This causes subsequent elements to be read from incorrect offsets and dereferenced as pointers, leading to untrusted pointer dereference and a denial of service condition.

An attacker can cause a denial of service by triggering the untrusted pointer dereference through crafted variable-length string datasets with multiple elements. There is no indication of privilege escalation, data disclosure, or code execution from the provided information.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the vulnerability affects versions before 2.1.1, upgrading to version 2.1.1 or later is likely the intended fix once confirmed by the vendor. Until then, avoid processing untrusted variable-length string datasets with multiple elements in binary mode using h5dump.