PowerDNS DNSdist Use-After-Free Vulnerability in EDNS Options Parsing via Lua

A use-after-free vulnerability has been identified in PowerDNS DNSdist versions 1.9.0 prior to 1.9.11 and 2.0.0 prior to 2.0.2. The issue arises when the DNSQuestion:getEDNSOptions method is used in custom Lua code, allowing an attacker to send crafted DNS queries that could refer to a modified version of the DNS packet. This manipulation can trigger a use-after-free condition, potentially leading to a crash and causing a denial-of-service situation.

Impact

Exploitation of this vulnerability can cause a crash of the DNSdist process, leading to a denial-of-service condition.

Remediation

Users can upgrade to PowerDNS DNSdist versions 1.9.12 or 2.0.3, where this vulnerability has been patched. Alternatively, the DNSQuestion:getEDNSOptions method can be avoided in custom Lua code.