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prosody
File
plugins/muc/request.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 | 9703:0cfb7b3593eb |
child | 12977:74b9e05af71e |
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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 jid_resource = require "util.jid".resource; module:hook("muc-disco#info", function(event) event.reply:tag("feature", {var = "http://jabber.org/protocol/muc#request"}):up(); end); local voice_request_form = require "util.dataforms".new({ title = "Voice Request"; { name = "FORM_TYPE"; type = "hidden"; value = "http://jabber.org/protocol/muc#request"; }, { name = "muc#jid"; type = "jid-single"; label = "User ID"; desc = "The user's JID (address)"; }, { name = "muc#roomnick"; type = "text-single"; label = "Room nickname"; desc = "The user's nickname within the room"; }, { name = "muc#role"; type = "list-single"; label = "Requested role"; value = "participant"; options = { "none", "visitor", "participant", "moderator", }; }, { name = "muc#request_allow"; type = "boolean"; label = "Grant voice to this person?"; desc = "Specify whether this person is able to speak in a moderated room"; value = false; } }); local function handle_request(room, origin, stanza, form) local occupant = room:get_occupant_by_real_jid(stanza.attr.from); local fields = voice_request_form:data(form); local event = { room = room; origin = origin; stanza = stanza; fields = fields; occupant = occupant; }; if occupant.role == "moderator" then module:log("debug", "%s responded to a voice request in %s", jid_resource(occupant.nick), room.jid); module:fire_event("muc-voice-response", event); else module:log("debug", "%s requested voice in %s", jid_resource(occupant.nick), room.jid); module:fire_event("muc-voice-request", event); end end module:hook("muc-voice-request", function(event) if event.occupant.role == "visitor" then local nick = jid_resource(event.occupant.nick); local formdata = { ["muc#jid"] = event.stanza.attr.from; ["muc#roomnick"] = nick; }; local message = st.message({ type = "normal"; from = event.room.jid }) :add_child(voice_request_form:form(formdata)); event.room:broadcast(message, function (_, occupant) return occupant.role == "moderator"; end); end end); module:hook("muc-voice-response", function(event) local actor = event.stanza.attr.from; local affected_occupant = event.room:get_occupant_by_real_jid(event.fields["muc#jid"]); local occupant = event.occupant; if occupant.role ~= "moderator" then module:log("debug", "%s tried to grant voice but wasn't a moderator", jid_resource(occupant.nick)); return; end if not event.fields["muc#request_allow"] then module:log("debug", "%s did not grant voice", jid_resource(occupant.nick)); return; end if not affected_occupant then module:log("debug", "%s tried to grant voice to unknown occupant %s", jid_resource(occupant.nick), event.fields["muc#jid"]); return; end if affected_occupant.role ~= "visitor" then module:log("debug", "%s tried to grant voice to %s but they already have it", jid_resource(occupant.nick), jid_resource(occupant.jid)); return; end module:log("debug", "%s granted voice to %s", jid_resource(event.occupant.nick), jid_resource(occupant.jid)); local ok, errtype, err = event.room:set_role(actor, affected_occupant.nick, "participant", "Voice granted"); if not ok then module:log("debug", "Error granting voice: %s", err or errtype); event.origin.send(st.error_reply(event.stanza, errtype, err)); end end); return { handle_request = handle_request; };