DNSdist Out-of-Bounds Access Flaws
2026-04-22
Out-of-bounds memory read in dnsdist allows remote attackers to trigger information disclosure or denial of service when custom Lua code invokes getDomainListByAddress() or getAddressListByDomain() functions on a crafted packet cache entry. The vulnerability requires network access but has high attack complexity, limiting real-world exploitation despite the remote attack vector.
DNSdist is vulnerable to denial of service via out-of-bounds write when processing crafted UDP responses from a rogue backend server. An attacker controlling a backend DNS server can send a specially crafted UDP response with a query ID set off-by-one from the maximum configured value, triggering memory corruption that crashes the DNS forwarder. The CVSS score of 6.5 reflects network attack vector with high complexity and absence of confidentiality impact, though availability and integrity are affected.