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plugins/muc/password.lib.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 | 9455:c62c983b8be3 |
child | 10447:b5fd1637f15c |
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-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- Copyright (C) 2014 Daurnimator -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local st = require "util.stanza"; local function get_password(room) return room._data.password; end local function set_password(room, password) if password == "" then password = nil; end if room._data.password == password then return false; end room._data.password = password; return true; end module:hook("muc-disco#info", function(event) event.reply:tag("feature", {var = get_password(event.room) and "muc_passwordprotected" or "muc_unsecured"}):up(); end); module:hook("muc-config-form", function(event) table.insert(event.form, { name = "muc#roomconfig_roomsecret"; type = "text-private"; label = "Password"; value = get_password(event.room) or ""; }); end, 90-2); module:hook("muc-config-submitted/muc#roomconfig_roomsecret", function(event) if set_password(event.room, event.value) then event.status_codes["104"] = true; end end); -- Don't allow anyone to join room unless they provide the password module:hook("muc-occupant-pre-join", function(event) local room, stanza = event.room, event.stanza; if not get_password(room) then return end local muc_x = stanza:get_child("x", "http://jabber.org/protocol/muc"); if not muc_x then return end local password = muc_x:get_child_text("password", "http://jabber.org/protocol/muc"); if not password or password == "" then password = nil; end if get_password(room) ~= password then local from, to = stanza.attr.from, stanza.attr.to; module:log("debug", "%s couldn't join due to invalid password: %s", from, to); local reply = st.error_reply(stanza, "auth", "not-authorized"):up(); reply.tags[1].attr.code = "401"; event.origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"})); return true; end end, -20); -- Add password to outgoing invite module:hook("muc-invite", function(event) local password = get_password(event.room); if password then local x = event.stanza:get_child("x", "http://jabber.org/protocol/muc#user"); x:tag("password"):text(password):up(); end end); module:hook("muc-room-pre-create", function (event) local stanza, room = event.stanza, event.room; local muc_x = stanza:get_child("x", "http://jabber.org/protocol/muc"); if not muc_x then return end local password = muc_x:get_child_text("password", "http://jabber.org/protocol/muc"); set_password(room, password); end); return { get = get_password; set = set_password; };