prosody
783056b4e448
spec/scansion/issue978.scs

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spec/scansion/issue978.scs @ 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 9291:329a670ae975
line wrap: on
line source

# Issue 978: MUC does not carry error into occupant leave status (single client)
[Client] Romeo
	jid: user@localhost
	password: password

[Client] Juliet
	jid: user2@localhost
	password: password

-----

Romeo connects

Romeo sends:
	<presence to="room@conference.localhost/Romeo">
		<x xmlns="http://jabber.org/protocol/muc"/>
	</presence>

Romeo receives:
	<presence from='room@conference.localhost/Romeo'>
		<x xmlns='http://jabber.org/protocol/muc#user'>
			<status code='201'/>
			<item jid="${Romeo's full JID}" affiliation='owner' role='moderator'/>
			<status code='110'/>
		</x>
	</presence>

Romeo receives:
	<message type='groupchat' from='room@conference.localhost'><subject/></message>

# Submit config form
Romeo sends:
	<iq id='config1' to='room@conference.localhost' type='set'>
		<query xmlns='http://jabber.org/protocol/muc#owner'>
			<x xmlns='jabber:x:data' type='submit'>
				<field var='FORM_TYPE'>
					<value>http://jabber.org/protocol/muc#roomconfig</value>
				</field>
				<field var='muc#roomconfig_whois'>
					<value>anyone</value>
				</field>
			</x>
		</query>
	</iq>

Romeo receives:
	<iq id="config1" from="room@conference.localhost" type="result">
	</iq>

# Juliet connects, and joins the room
Juliet connects

Juliet sends:
	<presence to="room@conference.localhost/Juliet">
		<x xmlns="http://jabber.org/protocol/muc"/>
	</presence>

Juliet receives:
	<presence from="room@conference.localhost/Romeo" />

Juliet receives:
	<presence from="room@conference.localhost/Juliet" />

Juliet receives:
	<message type='groupchat' from='room@conference.localhost'><subject/></message>

Romeo receives:
	<presence from="room@conference.localhost/Juliet" />

Juliet sends:
	<presence type='error' to='room@conference.localhost'>
		<error type='cancel'>
			<service-unavailable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
			<text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>Test error</text>
		</error>
	</presence>

Romeo receives:
	<presence type='unavailable' from='room@conference.localhost/Juliet'>
		<status>Kicked: service unavailable: Test error</status>
		<x xmlns='http://jabber.org/protocol/muc#user'>
			<status code='333'/>
			<item jid="${Juliet's full JID}" affiliation='none' role='none'/>
		</x>
	</presence>