Zephyr Out-of-Bounds Read Vulnerability in DNS QName Copy Function

A memory safety vulnerability has been identified in the Zephyr project, specifically in versions through 4.0. The issue arises in the 'dns_copy_qname' function within 'dns_pack.c', where a 'memcpy' operation is performed with an untrusted source buffer. The function fails to validate whether the source buffer is sufficiently large to accommodate the data being copied, leading to potential out-of-bounds reads.

Impact

This vulnerability can cause a crash and denial-of-service on embedded devices with memory protection. For devices lacking memory protection, it may result in incorrect and unpredictable behavior.

Remediation

Users can apply the patch available in the main branch or in the v3.7.0 and v4.0.0 tags. Instructions for applying the patch can be found in the Zephyr GitHub repository.