Premature Exit and Assertion Failure in BIND 9 Due to Query-Handling Code Flaw

CVE-2023-5517

What is CVE-2023-5517?

A vulnerability exists in the query-handling code of BIND 9 DNS servers, leading to a potential premature exit due to an assertion failure. This occurs when the server is configured with nxdomain-redirect <domain>;, in conjunction with receiving a PTR query for an RFC 1918 address, typically resulting in an authoritative NXDOMAIN response. The flaw affects several versions of BIND 9, indicating a risk that could impact DNS resolution across various network environments, necessitating timely updates and mitigations by system administrators.

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