File

plugins/mod_lastactivity.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 9224:a84dbd2e08bc
child 10750:ff087f2d4cb6
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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 is_contact_subscribed = require "core.rostermanager".is_contact_subscribed;
local jid_bare = require "util.jid".bare;
local jid_split = require "util.jid".split;

module:add_feature("jabber:iq:last");

local map = {};

module:hook("pre-presence/bare", function(event)
	local stanza = event.stanza;
	if not(stanza.attr.to) and stanza.attr.type == "unavailable" then
		local t = os.time();
		local s = stanza:get_child_text("status");
		map[event.origin.username] = {s = s, t = t};
	end
end, 10);

module:hook("iq-get/bare/jabber:iq:last:query", function(event)
	local origin, stanza = event.origin, event.stanza;
	local username = jid_split(stanza.attr.to) or origin.username;
	if not stanza.attr.to or is_contact_subscribed(username, module.host, jid_bare(stanza.attr.from)) then
		local seconds, text = "0", "";
		if map[username] then
			seconds = tostring(os.difftime(os.time(), map[username].t));
			text = map[username].s;
		end
		origin.send(st.reply(stanza):tag('query', {xmlns='jabber:iq:last', seconds=seconds}):text(text));
	else
		origin.send(st.error_reply(stanza, 'auth', 'forbidden'));
	end
	return true;
end);

module.save = function()
	return {map = map};
end
module.restore = function(data)
	map = data.map or {};
end