File

plugins/mod_iq.lua @ 12181:783056b4e448 0.11 0.11.12

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 8728:41c959c5c84b
child 12977:74b9e05af71e
line wrap: on
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--


local st = require "util.stanza";

local full_sessions = prosody.full_sessions;

if module:get_host_type() == "local" then
	module:hook("iq/full", function(data)
		-- IQ to full JID received
		local origin, stanza = data.origin, data.stanza;

		local session = full_sessions[stanza.attr.to];
		if not (session and session.send(stanza)) then
			if stanza.attr.type == "get" or stanza.attr.type == "set" then
				origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
			end
		end
		return true;
	end);
end

module:hook("iq/bare", function(data)
	-- IQ to bare JID received
	local stanza = data.stanza;
	local type = stanza.attr.type;

	-- TODO fire post processing events
	if type == "get" or type == "set" then
		local child = stanza.tags[1];
		local xmlns = child.attr.xmlns or "jabber:client";
		local ret = module:fire_event("iq/bare/"..xmlns..":"..child.name, data);
		if ret ~= nil then return ret; end
		return module:fire_event("iq-"..type.."/bare/"..xmlns..":"..child.name, data);
	else
		return module:fire_event("iq-"..type.."/bare/"..stanza.attr.id, data);
	end
end);

module:hook("iq/self", function(data)
	-- IQ to self JID received
	local stanza = data.stanza;
	local type = stanza.attr.type;

	if type == "get" or type == "set" then
		local child = stanza.tags[1];
		local xmlns = child.attr.xmlns or "jabber:client";
		local ret = module:fire_event("iq/self/"..xmlns..":"..child.name, data);
		if ret ~= nil then return ret; end
		return module:fire_event("iq-"..type.."/self/"..xmlns..":"..child.name, data);
	else
		return module:fire_event("iq-"..type.."/self/"..stanza.attr.id, data);
	end
end);

module:hook("iq/host", function(data)
	-- IQ to a local host received
	local stanza = data.stanza;
	local type = stanza.attr.type;

	if type == "get" or type == "set" then
		local child = stanza.tags[1];
		local xmlns = child.attr.xmlns or "jabber:client";
		local ret = module:fire_event("iq/host/"..xmlns..":"..child.name, data);
		if ret ~= nil then return ret; end
		return module:fire_event("iq-"..type.."/host/"..xmlns..":"..child.name, data);
	else
		return module:fire_event("iq-"..type.."/host/"..stanza.attr.id, data);
	end
end);