nginx + php 403 原因分析

环境：nginx + php

问题：

配置的网站，访问出现报错：Access Denied (403)

常见解决方法:

1、文件权限问题

可能是文件权限问题，没有读权限。

或者selinux没有关闭。

2、security.limit_extensions

查看nginx的错误日志error.log，发现有如下错误：

// :: [error] #: * FastCGI sent in stderr: "Access to the script '/home/www/game/10313156.html' has been denied (see security.limi
t_extensions)" while reading response header from......

从5.3.9开始，php官方加入了一个配置"security.limit_extensions"，默认只允许执行扩展名为".php"的文件，造成了其他类型的文件不支持的问题。

官方说明 ：
; Limits the extensions of the main script FPM will allow to parse. This can
; prevent configuration mistakes on the web server side. You should only limit
; FPM to .php extensions to prevent malicious users to use other extensions to
; exectute php code.
; Note: set an empty value to allow all extensions.
; Default Value: .php
;security.limit_extensions = .php .php3 .php4 .php5

修改php-fpm.conf：（加入需要的文件扩展名）
security.limit_extensions = .php .html .js .css .jpg .jpeg .gif .png .htm

3、cgi.fix_pathinfo

通过这种url访问，显示Acess denied 错误。

nginx错误日志：

// :: [error] #: * FastCGI sent in stderr: "Access to the script '/home/www/home.php/game/qr' has been denied (see security.limit_extensions)" while reading response header......

修改php.ini ：（cgi.fix_pathinfo 默认为1 ）

cgi.fix_pathinfo = 1

官方说明 ：
; cgi.fix_pathinfo provides *real* PATH_INFO/PATH_TRANSLATED support for CGI.  PHP's
; previous behaviour was to set PATH_TRANSLATED to SCRIPT_FILENAME, and to not grok
; what PATH_INFO is.  For more information on PATH_INFO, see the cgi specs.  Setting
; this to  will cause PHP CGI to fix its paths to conform to the spec.  A setting
; of zero causes PHP to behave as before.  Default is .  You should fix your scripts
; to use SCRIPT_FILENAME rather than PATH_TRANSLATED.
; http://php.net/cgi.fix-pathinfo

其实cgi.fix_pathinfo = 1 会引发文件类型错误解析漏洞，建议是设置 cgi.fix_pathinfo = 0 。

关于漏洞危害的详情，可参考：

http://www.cnblogs.com/batsing/p/nginx_bug1_attack.html

http://www.phpvim.net/web/php/security-risks-caused-by-fix-pathinfo.html

( 关于漏洞的理解：

　　当cgi.fix_pathinfo=1时，访问路径：/foo.jpg/file.php ，如果file.php文件不存在，则php解析器会试图猜测你要执行哪个文件，沿着路径往回找。如果foo.jpg存在， 并且包含php代码，php解析器就会去执行foo.jpg 。

　　当cgi.fix_pathinfo=0时，PHP 解释器仅尝试给出的路径，如果文件没有找到就停止处理。

)

但将 cgi.fix_pathinfo = 0 ，可能会导致很多MVC框架（如ThinkPHP）无法正常运行。

4、

在php.ini上设置了：open_basedir=/home:/tmp/:/proc/
重启php-fpm

访问网页，按ctrl + F5频繁刷新的时候，会报 Access Denied错误。Access Denied是偶尔才会出现，不是一直403 。

nginx错误日志记录：

// :: [error] #: * FastCGI sent in stderr: "PHP message: PHP Warning:  Unknown: open_basedir restriction in effect. File(/home/www/touch/web/index.php) is not within the allowed path(s): (/home/wwwroot:/tmp/:/proc/) in Unknown on line 0
PHP message: PHP Warning:  Unknown: failed to open stream: Operation not permitted in Unknown on line
Unable to open primary script: /home/www/touch/web/index.php (Permission denied)" while reading response header from upstream, client: 117.136.1.22, server: test.hjq.com, request: "GET /index.php?c=Zs&a=getcontent HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "test.hjq.com"

、In your nginx config file set fastcgi_pass to your socket address (e.g. unix:/var/run/php-fpm/php-fpm.sock;) instead of your server address and port.

、Check your SCRIPT_FILENAME fastcgi param and set it according to the location of your files.

、In your nginx config file include fastcgi_split_path_info ^(.+\.php)(/.+)$; in the location block where all the other fastcgi params are defined.

原文链接：http://stackoverflow.com/questions/23390531/access-denied-403-for-php-files-with-nginx-php-fpm

http://www.laruence.com/2010/05/20/1495.html