File

plugins/mod_user_account_management.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 8484:f591855f060d
child 10382:fcdc65bc6697
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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 usermanager_set_password = require "core.usermanager".set_password;
local usermanager_delete_user = require "core.usermanager".delete_user;
local nodeprep = require "util.encodings".stringprep.nodeprep;
local jid_bare = require "util.jid".bare;

local compat = module:get_option_boolean("registration_compat", true);

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

-- Password change and account deletion handler
local function handle_registration_stanza(event)
	local session, stanza = event.origin, event.stanza;
	local log = session.log or module._log;

	local query = stanza.tags[1];
	if stanza.attr.type == "get" then
		local reply = st.reply(stanza);
		reply:tag("query", {xmlns = "jabber:iq:register"})
			:tag("registered"):up()
			:tag("username"):text(session.username):up()
			:tag("password"):up();
		session.send(reply);
	else -- stanza.attr.type == "set"
		if query.tags[1] and query.tags[1].name == "remove" then
			local username, host = session.username, session.host;

			-- This one weird trick sends a reply to this stanza before the user is deleted
			local old_session_close = session.close;
			session.close = function(self, ...)
				self.send(st.reply(stanza));
				return old_session_close(self, ...);
			end

			local ok, err = usermanager_delete_user(username, host);

			if not ok then
				log("debug", "Removing user account %s@%s failed: %s", username, host, err);
				session.close = old_session_close;
				session.send(st.error_reply(stanza, "cancel", "service-unavailable", err));
				return true;
			end

			log("info", "User removed their account: %s@%s", username, host);
			module:fire_event("user-deregistered", { username = username, host = host, source = "mod_register", session = session });
		else
			local username = nodeprep(query:get_child_text("username"));
			local password = query:get_child_text("password");
			if username and password then
				if username == session.username then
					if usermanager_set_password(username, password, session.host, session.resource) then
						session.send(st.reply(stanza));
					else
						-- TODO unable to write file, file may be locked, etc, what's the correct error?
						session.send(st.error_reply(stanza, "wait", "internal-server-error"));
					end
				else
					session.send(st.error_reply(stanza, "modify", "bad-request"));
				end
			else
				session.send(st.error_reply(stanza, "modify", "bad-request"));
			end
		end
	end
	return true;
end

module:hook("iq/self/jabber:iq:register:query", handle_registration_stanza);
if compat then
	module:hook("iq/host/jabber:iq:register:query", function (event)
		local session, stanza = event.origin, event.stanza;
		if session.type == "c2s" and jid_bare(stanza.attr.to) == session.host then
			return handle_registration_stanza(event);
		end
	end);
end