服务器常见漏洞修复配置

最新推荐文章于 2025-06-17 17:52:19 发布

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#服务器 #运维 #ssl #java #tomcat

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本文介绍了处理应用程序错误消息的方法，包括配置500错误页面以隐藏敏感信息，以及在Tomcat和Nginx中的相应设置。此外，还详细讲解了如何防止XSS攻击，通过Java项目的过滤器XssFilter来过滤请求参数，确保Web应用的安全性。

记录一些遇见过的漏洞并处理方案备忘：应用程序错误消息，tomcat默认页面泄漏，nginx常用配置，xss攻击。

一、应用程序错误消息：

500的报错页面，一般会把错误信息返回到页面，但是漏洞扫描过不去，

1）配置500页面，隐藏错误信息，更改为比较友好的提示信息

2）web.xml 添加配置：

                <error-page>
                        <error-code>500</error-code>
                        <location>/WEB-INF/500.jsp</location>
                </error-page>
                <error-page>
                        <error-code>400</error-code>
                        <location>/WEB-INF/400.jsp</location>
                </error-page>
                <error-page>
                        <error-code>404</error-code>
                        <location>/WEB-INF/404.jsp</location>
                </error-page>
                <error-page>
                        <error-code>403</error-code>
                        <location>/WEB-INF/403.jsp</location>
                </error-page>

3）server.xml 添加配置：

二、tomcat默认页面泄漏

删除tomcat文件夹：/webapps/ROOT(删除原来的，新建一个空的)

/webapps/examples(删除)

/webapps/docs(删除)

三、nginx常用配置

        upstream pnxxxssh.mhedu.sh.cn { #服务器集群名字
                   server 127.0.0.1:8080 weight=90; #访问权重
                   server 119.3.146.11:8080 weight=10;    #访问权重
          }

                   server {#80端口监听，http自动转为https
                            listen 80;
                            server_name pnxxxssh.mhedu.sh.cn;
                            rewrite ^(.*) https://$server_name$1 permanent;
                    }

server {

listen 443;
server_name pnxxxssh.mhedu.sh.cn;
   ssl on;
   ssl_certificate _.mhedu.sh.cn.crt; #ssl证书
ssl_certificate_key _.mhedu.sh.cn.key;#ssl证书
ssl_session_timeout 5m;
ssl_protocols TLSv1.2; #使用TLS协议
   ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:HIGH:!ADH:!MD5;#加密套件的类型,ssl使用中等密码强度规则
ssl_prefer_server_ciphers on;
default_type 'text/html';
            charset ISO-88509-1;

location /flydi {
proxy_pass http://pnxxxssh.mhedu.sh.cn;
}

四、xss攻击：Java项目内解决

项目web.xml:

                        <filter>
                         <filter-name>XssFilter</filter-name>
                         <filter-class>com.*****.*****.common.filter.XssFilter</filter-class>
                        </filter>
                        <filter-mapping>
                         <filter-name>XssFilter</filter-name>
                         <url-pattern>/*</url-pattern>
                         <dispatcher>REQUEST</dispatcher>
                        </filter-mapping>

XssFilter：

package com.*****.*****.common.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

public class XssFilter implements Filter {
   FilterConfig filterConfig = null;
   @Override
   public void init(FilterConfig filterConfig) throws ServletException {
       // TODO Auto-generated method stub
       this.filterConfig = filterConfig;
   }

   @Override
   public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
           throws IOException, ServletException {
       // TODO Auto-generated method stub
       chain.doFilter(new XssHttpServletRequestWrapperNew(
   (HttpServletRequest) request), response);
   }

   @Override
   public void destroy() {
       // TODO Auto-generated method stub
       this.filterConfig = null;
   }

}

XssHttpServletRequestWrapperNew：

package com.*****.*****.common.filter;

import java.text.CharacterIterator;
import java.text.StringCharacterIterator;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class XssHttpServletRequestWrapperNew extends HttpServletRequestWrapper{
HttpServletRequest orgRequest = null;

public XssHttpServletRequestWrapperNew(HttpServletRequest request) {
super(request);
orgRequest = request;
}

/**
* 覆盖getParameter方法，将参数名和参数值都做xss过滤。
* 如果需要获得原始的值，则通过super.getParameterValues(name)来获取
* getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
*/
@Override
public String getParameter(String name) {
String value = super.getParameter(xssEncode(name));
if (value != null) {
value = xssEncode(value);
value = HTMLEncode(value);
}
return value;
}

/**
* 对一些特殊字符进行转义
*/
public static String HTMLEncode(String aText){
final StringBuilder result = new StringBuilder();
final StringCharacterIterator iterator = new StringCharacterIterator(aText);
char character = iterator.current();
while (character != CharacterIterator.DONE ){
if (character == '<') {
result.append("<");
} else if (character == '>') {
result.append(">");
} else if (character == '&') {
result.append("&");
} else if (character == '\"') {
result.append(""");
} else {
result.append(character);
}
character = iterator.next();
}
return result.toString();
}

/**
* 覆盖getHeader方法，将参数名和参数值都做xss过滤。如果需要获得原始的值，则通过super.getHeaders(name)来获取
* getHeaderNames 也可能需要覆盖
*/
@Override
public String getHeader(String name) {
String value = super.getHeader(xssEncode(name));
if (value != null) {
value = xssEncode(value);
}
return value;
}

/**
* 将容易引起xss漏洞的半角字符直接替换成全角字符
* 目前xssProject对注入代码要求是必须开始标签和结束标签(如<script></script>)正确匹配才能解析，否则报错；因此只能替换调xssProject换为自定义实现
* @param s
* @return
*/
private static String xssEncode(String s) {
if (s == null || s.isEmpty()) {
return s;
}

String result = stripXSS(s);
if (null != result) {
result = escape(result);
}

return result;

}

public static String escape(String s) {
StringBuilder sb = new StringBuilder(s.length() + 16);
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
switch (c) {
case '>':
sb.append('＞');// 全角大于号
break;
case '<':
sb.append('＜');// 全角小于号
break;
case '\'':
sb.append('‘');// 全角单引号
break;
case '\"':
sb.append('“');// 全角双引号
break;
case '\\':
sb.append('＼');// 全角斜线
break;
case '%':
sb.append('％'); // 全角冒号
break;
default:
sb.append(c);
break;
}

}
return sb.toString();
}

private static String stripXSS(String value) {
if (value != null) {

// Avoid null characters
value = value.replaceAll("", "");
// Avoid anything between script tags
Pattern scriptPattern = Pattern.compile("<script>(.*?)</script>",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid anything in a src='...' type of expression
scriptPattern = Pattern.compile("src[\r\n]*=[\r\n]*\\\'(.*?)\\\'",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("src[\r\n]*=[\r\n]*\\\"(.*?)\\\"",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome </script> tag
scriptPattern = Pattern.compile("</script>",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome <script ...> tag
scriptPattern = Pattern.compile("<script(.*?)>",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid eval(...) expressions
scriptPattern = Pattern.compile("eval\$(.*?)\$",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid expression(...) expressions
scriptPattern = Pattern.compile("expression\$(.*?)\$",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid javascript:... expressions
scriptPattern = Pattern.compile("javascript:",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid vbscript:... expressions
scriptPattern = Pattern.compile("vbscript:",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid οnlοad= expressions
scriptPattern = Pattern.compile("onload(.*?)=",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");

scriptPattern = Pattern.compile("<iframe>(.*?)</iframe>",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");

scriptPattern = Pattern.compile("</iframe>",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome <script ...> tag
scriptPattern = Pattern.compile("<iframe(.*?)>",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
}
return value;
}

/**
* 获取最原始的request
*
* @return
*/
public HttpServletRequest getOrgRequest() {
return orgRequest;
}

/**
* 获取最原始的request的静态方法
*
* @return
*/
public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
if (req instanceof XssHttpServletRequestWrapperNew) {
return ((XssHttpServletRequestWrapperNew) req).getOrgRequest();
}

return req;
}
}