modsecurity原本是Apache上的一款开源waf,可以有效的增强web安全性,目前已经支持nginx和IIS,配合nginx的灵活和高效,可以打造成生产级的WAF,是保护和审核web安全的利器。
系统:centos 6.5 64位、 tengine 2.1.0, modsecurity 2.8.0
tengine : http://tengine.taobao.org/download/tengine-2.1.0.tar.gz
modsecurity for Nginx: https://www.modsecurity.org/tarball/2.8.0/modsecurity-2.8.0.tar.gz
OWASP规则集: https://github.com/SpiderLabs/owasp-modsecurity-crs
依赖关系:
tengine(nginx)依赖: pcre 、zlib、 openssl, 这三个包centos 6.5 系统源里都有:
yum install zlib zlib-devel openssl openssl-devel pcre pcre-devel
modsecurty依赖的包:pcre httpd-devel libxml2 apr
yum install httpd-devel apr apr-util-devel apr-devel pcre pcre-devel libxml2 libxml2-devel
下载modsecurity for nginx 解压,进入解压后目录执行:
./autogen.sh ./configure --enable-standalone-module --disable-mlogc make
在编译standalone后,nginx编译时可以通过"--add-module"添加modsecurity模块:
./configure --add-module=/root/modsecurity-2.8.0/nginx/modsecurity/ --prefix=/opt/tengine make && make install
modsecurity倾向于过滤和阻止web危险,之所以强大就在于规则,OWASP提供的规则是于社区志愿者维护的,被称为核心规则CRS(corerules),规则可靠强大,当然也可以自定义规则来满足各种需求。
git clone https://github.com/SpiderLabs/owasp-modsecurity-crs mv owasp-modsecurity-crs /opt/tengine/conf/ cd /opt/tengine/conf/owasp-modsecurity-crs && mv modsecurity_crs_10_setup.conf.example modsecurity_crs_10_setup.conf
复制modsecurity源码目录下的modsecurity.conf-recommended和unicode.mapping到nginx的conf目录下,并将modsecurity.conf-recommended重新命名为modsecurity.conf。
编辑modsecurity.conf 文件,将SecRuleEngine设置为 on
owasp-modsecurity-crs下有很多存放规则的文件夹,例如base_rules、experimental_rules、optional_rules、slr_rules,里面的规则按需要启用,需要启用的规则使用Include进来即可。
Include owasp-modsecurity-crs/modsecurity_crs_10_setup.conf Include owasp-modsecurity-crs/base_rules/modsecurity_crs_41_sql_injection_attacks.conf Include owasp-modsecurity-crs/base_rules/modsecurity_crs_41_xss_attacks.conf Include owasp-modsecurity-crs/base_rules/modsecurity_crs_40_generic_attacks.conf Include owasp-modsecurity-crs/experimental_rules/modsecurity_crs_11_dos_protection.conf Include owasp-modsecurity-crs/experimental_rules/modsecurity_crs_11_brute_force.conf Include owasp-modsecurity-crs/optional_rules/modsecurity_crs_16_session_hijacking.conf
在需要启用modsecurity的主机的location下面加入下面两行即可:
ModSecurityEnabled on; ModSecurityConfig modsecurity.conf;
下面是两个示例配置,php虚拟主机:
server { listen 80; server_name 52os.net www.52os.net; location ~ \.php$ { ModSecurityEnabled on; ModSecurityConfig modsecurity.conf; root /web/wordpress; index index.php index.html index.htm; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $Document_root$fastcgi_script_name; include fastcgi_params; } }
upstream负载均衡:
upstream 52os.net { server 192.168.1.100:8080; server 192.168.1.101:8080 backup; } server { listen 80; server_name 52os.net www.52os.net; location / { ModSecurityEnabled on; ModSecurityConfig modsecurity.conf; proxy_pass http://online; proxy_redirect off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } }
我们启用了xss和sql注入的过滤,不正常的请求会直接返回403。以php环境为例,新建一个phpinfo.php内容为:
<?php phpinfo(); ?>
在浏览器中访问:
http://www.52os.net/phpinfo.php?id=1 正常显示。 http://www.52os.net/phpinfo.php?id=1 and 1=1 返回403。 http://www.52os.net/phpinfo.php?search=<scritp>alert('xss');</script> 返回403。
说明sql注入和xss已经被过滤了
1.缺少APXS会报错
configure: looking for Apache module support via DSO through APXS configure: error: couldn't find APXS
apxs是一个为Apache HTTP服务器编译和安装扩展模块的工具,用于编译一个或多个源程序或目标代码文件为动态共享对象。
解决方法:
yum install httpd-devel
2.没有pcre
configure: *** pcre library not found. configure: error: pcre library is required
解决方法:
yum install pcre pcre-devel
3.没有libxml2
configure: *** xml library not found. configure: error: libxml2 is required
解决方法:
yum install libxml2 libxml2-devel
4.执行 /opt/tengine/sbin/nginx -m
时有警告
Tengine version: Tengine/2.1.0 (nginx/1.6.2) nginx: [warn] ModSecurity: Loaded APR do not match with compiled!
原因:modsecurity编译时和加载时的apr版本不一致造成的,并且会有以下error.log
2015/01/26 02:04:18 [notice] 29036#0: ModSecurity for nginx (STABLE)/2.8.0 () configured. 2015/01/26 02:04:18 [notice] 29036#0: ModSecurity: APR compiled version="1.5.0"; loaded version="1.3.9" 2015/01/26 02:04:18 [warn] 29036#0: ModSecurity: Loaded APR do not match with compiled! 2015/01/26 02:04:18 [notice] 29036#0: ModSecurity: PCRE compiled version="7.8 "; loaded version="7.8 2008-09-05" 2015/01/26 02:04:18 [notice] 29036#0: ModSecurity: LIBXML compiled version="2.7.6" 2015/01/26 02:04:18 [notice] 29036#0: Status engine is currently disabled, enable it by set SecStatusEngine to On.
解决方法,移除低版本的APR (1.3.9)
yum remove apr
5.Error.log中有: Audit log: Failed to lock global mutex
2015/01/26 04:15:42 [error] 61610#0: [client 10.11.15.161] ModSecurity: Audit log: Failed to lock global mutex: Permission denied [hostname ""] [uri "/i.php"] [unique_id "AcAcAcAcAcAcAcA4DcA7AcAc"]
解决方法:
编辑modsecurity.conf,注释掉默认的SecAuditLogType和SecAuditLog,添加以下内容:
SecAuditLogDirMode 0777 SecAuditLogFileMode 0550 SecAuditLogStorageDir /var/log/modsecurity SecAuditLogType Concurrent
参考文章:
https://github.com/SpiderLabs/ModSecurity/wiki/Reference-Manual#Installation_for_NGINX
http://drops.wooyun.org/tips/2614