PowerDNS Security Advisory 2006-02: Zero second CNAME TTLs can make PowerDNS exhaust allocated stack space, and crash
- CVE: CVE-2006-4252
- Date: 13th of November 2006
- Affects: PowerDNS Recursor versions 3.1.3 and earlier, on all
operating systems.
- Not affected: No versions of the PowerDNS Authoritative Server
(‘pdns_server’) are affected.
- Severity: Moderate
- Impact: Denial of service
- Exploit: This problem can be triggered by sending queries for
specifically configured domains
- Solution: Upgrade to PowerDNS Recursor 3.1.4, or apply commit
919.
- Workaround: None known. Exposure can be limited by configuring the
allow-from setting so only trusted users can query your
nameserver.
PowerDNS would recurse endlessly on encountering a CNAME loop consisting
entirely of zero second CNAME records, eventually exceeding resources
and crashing.