在配置文件添加如下字段即可
server {
## 禁SQL注入 Block SQL injections
set $block_sql_injections 0;
if ($query_string ~ “union.*select.*\(“) {
set $block_sql_injections 1;
}
if ($query_string ~ “union.*all.*select.*”) {
set $block_sql_injections 1;
}
if ($query_string ~ “concat.*\(“) {
set $block_sql_injections 1;
}
if ($block_sql_injections = 1) {
return 444;
}

## 禁掉文件注入
set $block_file_injections 0;
if ($query_string ~ “[a-zA-Z0-9_]=http://”) {
set $block_file_injections 1;
}
if ($query_string ~ “[a-zA-Z0-9_]=(\.\.//?)+”) {
set $block_file_injections 1;
}
if ($query_string ~ “[a-zA-Z0-9_]=/([a-z0-9_.]//?)+”) {
set $block_file_injections 1;
}
if ($block_file_injections = 1) {
return 444;
}

###一句话木马

if ( $query_string ~* ".*[\;'\<\>].*" ){
return 404;
}

 

## 禁掉溢出攻击
set $block_common_exploits 0;
if ($query_string ~ “(<|%3C).*script.*(>|%3E)”) {
set $block_common_exploits 1;
}
if ($query_string ~ “GLOBALS(=|\[|\%[0-9A-Z]{0,2})”) {
set $block_common_exploits 1;
}
if ($query_string ~ “_REQUEST(=|\[|\%[0-9A-Z]{0,2})”) {
set $block_common_exploits 1;
}
if ($query_string ~ “proc/self/environ”) {
set $block_common_exploits 1;
}
if ($query_string ~ “mosConfig_[a-zA-Z_]{1,21}(=|\%3D)”) {
set $block_common_exploits 1;
}
if ($query_string ~ “base64_(en|de)code\(.*\)”) {
set $block_common_exploits 1;
}
if ($block_common_exploits = 1) {
return 444;
}

## 禁spam字段
set $block_spam 0;
if ($query_string ~ “\b(ultram|unicauca|valium|viagra|vicodin|xanax|ypxaieo)\b”) {
set $block_spam 1;
}
if ($query_string ~ “\b(erections|hoodia|huronriveracres|impotence|levitra|libido)\b”) {
set $block_spam 1;
}
if ($query_string ~ “\b(ambien|blue\spill|cialis|cocaine|ejaculation|erectile)\b”) {
set $block_spam 1;
}
if ($query_string ~ “\b(lipitor|phentermin|pro[sz]ac|sandyauer|tramadol|troyhamby)\b”) {
set $block_spam 1;
}
if ($block_spam = 1) {
return 444;
}

## 禁掉user-agents
set $block_user_agents 0;

# Don’t disable wget if you need it to run cron jobs!
#if ($http_user_agent ~ “Wget”) {
# set $block_user_agents 1;
#}

# Disable Akeeba Remote Control 2.5 and earlier
if ($http_user_agent ~ “Indy Library”) {
set $block_user_agents 1;
}

# Common bandwidth hoggers and hacking tools.
if ($http_user_agent ~ “libwww-perl”) {
set $block_user_agents 1;
}
if ($http_user_agent ~ “GetRight”) {
set $block_user_agents 1;
}
if ($http_user_agent ~ “GetWeb!”) {
set $block_user_agents 1;
}
if ($http_user_agent ~ “Go!Zilla”) {
set $block_user_agents 1;
}
if ($http_user_agent ~ “Download Demon”) {
set $block_user_agents 1;
}
if ($http_user_agent ~ “Go-Ahead-Got-It”) {
set $block_user_agents 1;
}
if ($http_user_agent ~ “TurnitinBot”) {
set $block_user_agents 1;
}
if ($http_user_agent ~ “GrabNet”) {
set $block_user_agents 1;
}
    if ($http_user_agent ~ "WebBench") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "ApacheBench") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ ^$) {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "Python-urllib") {
        set $block_user_agents 1;
    }
if ($block_user_agents = 1) {
return 444;
}
}

说明:防sql注入/溢出攻击/spam采用禁掉URL中包含的字段实现,请根据需要合理添加
返回444,是完全不回应客户端,比403更加非常节省系统资源
转载  http://www.howtoforge.com/nginx-how-to-block-exploits-sql-injections-file-injections-spam-user-agents-etc

####sql####

 if ($request_uri ~* "(cost\()|(concat\()") {
                return 444;
        }
        if ($request_uri ~* "[+|(%20)]union[+|(%20)]") {
                return 444;
        }
        if ($request_uri ~* "[+|(%20)]and[+|(%20)]") {
                return 444;
        }
        if ($request_uri ~* "[+|(%20)]select[+|(%20)]") {
                return 444;
        } 

## Block SQL injections
    set $block_sql_injections 0;
    if ($query_string ~ "union.*select.*\(") {
        set $block_sql_injections 1;
    }
    if ($query_string ~ "union.*all.*select.*") {
        set $block_sql_injections 1;
    }
    if ($query_string ~ "concat.*\(") {
        set $block_sql_injections 1;
    }
    if ($block_sql_injections = 1) {
        return 403;
    }

    ## Block file injections
    set $block_file_injections 0;
    if ($query_string ~ "[a-zA-Z0-9_]=http://") {
        set $block_file_injections 1;
    }
    if ($query_string ~ "[a-zA-Z0-9_]=(\.\.//?)+") {
        set $block_file_injections 1;
    }
    if ($query_string ~ "[a-zA-Z0-9_]=/([a-z0-9_.]//?)+") {
        set $block_file_injections 1;
    }
    if ($block_file_injections = 1) {
        return 403;
    }

    ## Block common exploits
    set $block_common_exploits 0;
    if ($query_string ~ "(<|%3C).*script.*(>|%3E)") {
        set $block_common_exploits 1;
    }
    if ($query_string ~ "GLOBALS(=|\[|\%[0-9A-Z]{0,2})") {
        set $block_common_exploits 1;
    }
    if ($query_string ~ "_REQUEST(=|\[|\%[0-9A-Z]{0,2})") {
        set $block_common_exploits 1;
    }
    if ($query_string ~ "proc/self/environ") {
        set $block_common_exploits 1;
    }
    if ($query_string ~ "mosConfig_[a-zA-Z_]{1,21}(=|\%3D)") {
        set $block_common_exploits 1;
    }
    if ($query_string ~ "base64_(en|de)code\(.*\)") {
        set $block_common_exploits 1;
    }
    if ($block_common_exploits = 1) {
        return 403;
    }

    ## Block spam
    set $block_spam 0;
    if ($query_string ~ "\b(ultram|unicauca|valium|viagra|vicodin|xanax|ypxaieo)\b") {
        set $block_spam 1;
    }
    if ($query_string ~ "\b(erections|hoodia|huronriveracres|impotence|levitra|libido)\b") {
        set $block_spam 1;
    }
    if ($query_string ~ "\b(ambien|blue\spill|cialis|cocaine|ejaculation|erectile)\b") {
        set $block_spam 1;
    }
    if ($query_string ~ "\b(lipitor|phentermin|pro[sz]ac|sandyauer|tramadol|troyhamby)\b") {
        set $block_spam 1;
    }
    if ($block_spam = 1) {
        return 403;
    }

    ## Block user agents
    set $block_user_agents 0;

    # Don't disable wget if you need it to run cron jobs!
    #if ($http_user_agent ~ "Wget") {
    #    set $block_user_agents 1;
    #}

    # Disable Akeeba Remote Control 2.5 and earlier
    if ($http_user_agent ~ "Indy Library") {
        set $block_user_agents 1;
    }

    # Common bandwidth hoggers and hacking tools.
    if ($http_user_agent ~ "libwww-perl") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "GetRight") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "GetWeb!") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "Go!Zilla") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "Download Demon") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "Go-Ahead-Got-It") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "TurnitinBot") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "GrabNet") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "WebBench") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "ApacheBench") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ ^$) {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "Python-urllib") {
        set $block_user_agents 1;
    }
    if ($block_user_agents = 1) {
        return 403;
    }
 

这些规则必须要测试 才能上线。根据实际情况应用!!!