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util/datetime.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 | 9698:e616c37756b3 |
child | 12629:4c1d3f817063 |
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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. -- -- XEP-0082: XMPP Date and Time Profiles local os_date = os.date; local os_time = os.time; local os_difftime = os.difftime; local tonumber = tonumber; local _ENV = nil; -- luacheck: std none local function date(t) return os_date("!%Y-%m-%d", t); end local function datetime(t) return os_date("!%Y-%m-%dT%H:%M:%SZ", t); end local function time(t) return os_date("!%H:%M:%S", t); end local function legacy(t) return os_date("!%Y%m%dT%H:%M:%S", t); end local function parse(s) if s then local year, month, day, hour, min, sec, tzd; year, month, day, hour, min, sec, tzd = s:match("^(%d%d%d%d)%-?(%d%d)%-?(%d%d)T(%d%d):(%d%d):(%d%d)%.?%d*([Z+%-]?.*)$"); if year then local now = os_time(); local time_offset = os_difftime(os_time(os_date("*t", now)), os_time(os_date("!*t", now))); -- to deal with local timezone local tzd_offset = 0; if tzd ~= "" and tzd ~= "Z" then local sign, h, m = tzd:match("([+%-])(%d%d):?(%d*)"); if not sign then return; end if #m ~= 2 then m = "0"; end h, m = tonumber(h), tonumber(m); tzd_offset = h * 60 * 60 + m * 60; if sign == "-" then tzd_offset = -tzd_offset; end end sec = (sec + time_offset) - tzd_offset; return os_time({year=year, month=month, day=day, hour=hour, min=min, sec=sec, isdst=false}); end end end return { date = date; datetime = datetime; time = time; legacy = legacy; parse = parse; };