File

plugins/mod_admin_socket.lua @ 12180:53e0ae770917

util.xml: Do not allow doctypes, comments or processing instructions Yes. This is as bad as it sounds. CVE pending. In Prosody itself, this only affects mod_websocket, which uses util.xml to parse the <open/> frame, thus allowing unauthenticated remote DoS using Billion Laughs. However, third-party modules using util.xml may also be affected by this. This commit installs handlers which disallow the use of doctype declarations and processing instructions without any escape hatch. It, by default, also introduces such a handler for comments, however, there is a way to enable comments nontheless. This is because util.xml is used to parse human-facing data, where comments are generally a desirable feature, and also because comments are generally harmless.
author Jonas Schäfer <jonas@wielicki.name>
date Mon, 10 Jan 2022 18:23:54 +0100
parent 10866:5265f7fe11dd
child 12392:5373724e08a5
line wrap: on
line source

module:set_global();

local have_unix, unix = pcall(require, "socket.unix");

if not have_unix or type(unix) ~= "table" then
	module:log_status("error", "LuaSocket unix socket support not available or incompatible, ensure it is up to date");
	return;
end

local server = require "net.server";

local adminstream = require "util.adminstream";

local socket_path = module:get_option_path("admin_socket", "prosody.sock", "data");

local sessions = module:shared("sessions");

local function fire_admin_event(session, stanza)
	local event_data = {
		origin = session, stanza = stanza;
	};
	local event_name;
	if stanza.attr.xmlns then
		event_name = "admin/"..stanza.attr.xmlns..":"..stanza.name;
	else
		event_name = "admin/"..stanza.name;
	end
	module:log("debug", "Firing %s", event_name);
	return module:fire_event(event_name, event_data);
end

module:hook("server-stopping", function ()
	for _, session in pairs(sessions) do
		session:close("system-shutdown");
	end
	os.remove(socket_path);
end);

--- Unix domain socket management

local conn, sock;

local listeners = adminstream.server(sessions, fire_admin_event).listeners;

local function accept_connection()
	module:log("debug", "accepting...");
	local client = sock:accept();
	if not client then return; end
	server.wrapclient(client, "unix", 0, listeners, "*a");
end

function module.load()
	sock = unix.stream();
	sock:settimeout(0);
	os.remove(socket_path);
	assert(sock:bind(socket_path));
	assert(sock:listen());
	if server.wrapserver then
		conn = server.wrapserver(sock, socket_path, 0, listeners);
	else
		conn = server.watchfd(sock:getfd(), accept_connection);
	end
end

function module.unload()
	if conn then
		conn:close();
	end
	if sock then
		sock:close();
	end
	os.remove(socket_path);
end