Unbound < 1.5.1 Delegation Handling Recursive Referral Handling Resource Exhaustion DoS
Medium Nessus Plugin ID 87870
Synopsis
The remote name server is affected by a denial of service vulnerability.
Description
According to its self-reported version number, the remote Unbound DNS resolver is affected by a denial of service vulnerability in the Domain Name Service due to improper handling of a maliciously-constructed zone or queries from a rogue server. An unauthenticated, remote attacker can exploit this, via a specially crafted request, to cause the service to issue unlimited queries in an attempt to follow a delegation, resulting in a denial of service condition.
Solution
Upgrade to Unbound version 1.5.1 or later. Alternatively, apply the patch provided by the vendor.