Comment by strenholme

12 hours ago

I should explain how MaraDNS uses Lua 5.1 (actually, Lunacy, my own fork with security bugs fixed as well as security hardening—including, yes, a patch against CVE-2014-5461), so you can get an idea of its attack surface.

MaraDNS has three components:

• MaraDNS, the authoritative server, which goes back all the way to 2001

• Deadwood, the recursive server, which was started back in 2007

• coLunacyDNS, which allows a DNS server to use Lua scripting; this didn’t exist until the COVID pandemic

Neither MaraDNS nor Deadwood use Lunacy (except as a scripting engine for converting documents); only coLunacyDNS uses Lunacy. coLunacyDNS uses a sandboxed and security hardened version of Lunacy (and, yes, I would accept bugs where someone could escape that sandbox), and the Lua scripts which coLunacyDNS uses can only be controlled by a local user and there is no capability to run Lua scripts remotely.

> coLunacyDNS, which allows a DNS server to use Lua scripting; this didn’t exist until the COVID pandemic

Why would a DNS server use Lua scripting? Is this for dynamically responding to requests rather than doing a pure lookup?