CVE-2025-62408

The `ares_parse_naptr_reply()` function in the c-ares library may read memory outside of the given input buffer if the passed DNS response packet is crafted in a specific way.

Heap-based buffer overflow in the ares_create_query function in c-ares 1.x before 1.12.0 allows remote attackers to cause a denial of service or possibly execute arbitrary code via a hostname with an escaped trailing dot.

In c-ares prior to 1.34.7, ares_dns_parse() trusted attacker-controlled ANCOUNT, NSCOUNT, and ARCOUNT fields before confirming the DNS response contained enough bytes. A malicious DNS response could cause disproportionate heap allocation for a tiny message, degrading or denying name resolution.

c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_name_parse() enforces backward DNS compression pointers but does not bound the total pointer hops or assembled name length. A malicious DNS server can send a response containing a long descending pointer chain and many resource records whose NAME or RDATA fields refer to the chain, causing repeated decompression work that grows quadratically with message size.

c-ares is an asynchronous resolver library. From version 1.32.3 until 1.34.7, a use-after-free / double-free vulnerability exists in query-completion handling. The same flaw is present at multiple points in the resend/finish path.