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util/logger.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 | 8556:5800f0c7afd6 |
child | 12394:86d6b069b892 |
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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. -- -- luacheck: ignore 213/level local pairs = pairs; local ipairs = ipairs; local require = require; local _ENV = nil; -- luacheck: std none local level_sinks = {}; local make_logger; local function init(name) local log_debug = make_logger(name, "debug"); local log_info = make_logger(name, "info"); local log_warn = make_logger(name, "warn"); local log_error = make_logger(name, "error"); return function (level, message, ...) if level == "debug" then return log_debug(message, ...); elseif level == "info" then return log_info(message, ...); elseif level == "warn" then return log_warn(message, ...); elseif level == "error" then return log_error(message, ...); end end end function make_logger(source_name, level) local level_handlers = level_sinks[level]; if not level_handlers then level_handlers = {}; level_sinks[level] = level_handlers; end local logger = function (message, ...) for i = 1,#level_handlers do level_handlers[i](source_name, level, message, ...); end end return logger; end local function reset() for level, handler_list in pairs(level_sinks) do -- Clear all handlers for this level for i = 1, #handler_list do handler_list[i] = nil; end end end local function add_level_sink(level, sink_function) if not level_sinks[level] then level_sinks[level] = { sink_function }; else level_sinks[level][#level_sinks[level] + 1 ] = sink_function; end end local function add_simple_sink(simple_sink_function, levels) local format = require "util.format".format; local function sink_function(name, level, msg, ...) return simple_sink_function(name, level, format(msg, ...)); end for _, level in ipairs(levels or {"debug", "info", "warn", "error"}) do add_level_sink(level, sink_function); end end return { init = init; make_logger = make_logger; reset = reset; add_level_sink = add_level_sink; add_simple_sink = add_simple_sink; new = make_logger; };