3 ms·
No. Recursive resolvers do not use getaddrinfo(3) to resolve DNS queries.
by inopinatus 11y ago
No. Recursive resolvers do not use getaddrinfo(3) to resolve DNS queries.
- weinzierl 11y agoThat was what I was thinking but it was stupid idea. My point is that if you could use this bug to use one rogue DNS to own other DNSes this could be leveraged to bring large parts of the Internet down. I don't know how hard or easy this could be. A quick glance into PDNS reveals four calls to getaddrinfo()[1]. So it might be possible... [1] https://github.com/PowerDNS/pdns/search?utf8=%E2%9C%93&q=getaddrinfo https://github.com/PowerDNS/pdns/search?utf8=%E2%9C%93&q=get...
- JdeBP 11y agoOut of those four calls: One uses AI_NUMERICHOST and thus doesn't do any DNS client activity. A second isn't supplied arbitrary domain names as input, they being the ones configured for the location of a specific back-end data source by the server administrator. The third is used only inside a "zone transfer" subsystem and again isn't supplied arbitrary domain names as input, the domain names again being in local data specified by the server administrator. And the fourth is not even part of the executable program, the code being disabled with #if 0 . The "S" in "DNS" stands for "system", not "server", by the way. A rogue DNS server would "own" other DNS servers.