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plugins/mod_uptime.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 | 9572:867e40b82409 |
child | 10565:421b2f8369fd |
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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 start_time = prosody.start_time; module:hook_global("server-started", function() start_time = prosody.start_time end); -- XEP-0012: Last activity module:add_feature("jabber:iq:last"); module:hook("iq-get/host/jabber:iq:last:query", function(event) local origin, stanza = event.origin, event.stanza; origin.send(st.reply(stanza):tag("query", {xmlns = "jabber:iq:last", seconds = tostring(os.difftime(os.time(), start_time))})); return true; end); -- Ad-hoc command module:depends "adhoc"; local adhoc_new = module:require "adhoc".new; function uptime_text() local t = os.time()-prosody.start_time; local seconds = t%60; t = (t - seconds)/60; local minutes = t%60; t = (t - minutes)/60; local hours = t%24; t = (t - hours)/24; local days = t; return string.format("This server has been running for %d day%s, %d hour%s and %d minute%s (since %s)", days, (days ~= 1 and "s") or "", hours, (hours ~= 1 and "s") or "", minutes, (minutes ~= 1 and "s") or "", os.date("%c", prosody.start_time)); end function uptime_command_handler () return { info = uptime_text(), status = "completed" }; end local descriptor = adhoc_new("Get uptime", "uptime", uptime_command_handler); module:provides("adhoc", descriptor);