CEH v10: 13_Hacking_Web_Servers

Web Server

Web Servers are the programs that are used for hosting services.

Web Servers are deployed on a separate web server hardware or installed on a host as a program.

It delivers content over Hyper Text Transfer Protocol (HTTP).

Web Servers support different types of application extensions whereas all of the support Hypertext Markup Language (HTML).

Web Server Security Issue

Web server vulnerabilities:

  • Improper permission of file directories
  • Default configurations
  • Enabling unnecessary services
  • Lack of security
  • Bugs
  • Misconfigured SSL certificate
  • Enabled debugging

Open Source Web Servers

  • Apache HTTP Server
  • Nginx
  • Apache Tomcat
  • Lighttpd

Internet Information Services (IIS)

IIS is a Windows-based webserver.

Components of IIS

  • Protocol listener are responsible for receiving and returning protocol-specific requests.
  • HTTP.sys are responsible for HTTP requests.
  • World Wide Web Publishing Service (WWW Service)
  • Windows Process Activation Service (WAS)

Web Server Attacks

DoS/DDoS

DNS Server Hijacking

DNS Amplification Attack

Spoof the source address of the DNS request, by the amplification of the size of the request and using botnets, it results a DDoS attack.

Directory Traversal Attacks

Attacker using trials and error method to access restricted directories to reveal sensitive information.

Man-in-the-Middle / Sniffing Attacks

Phishing Attacks

Website Defacement

After a successful intrusion, attacker alters and modify the content of the website.

Webserver Misconfiguration

Attacker looks for misconfigurations and vulnerabilities to exploit.

HTTP Response Splitting Attack

Read more here

Web Cache Poisoning Attack

The attacker wipe the actual cache of the webserver and sending crafted request to store fake entries.

Web Application Attacks

  • Cookie Tampering
  • DoS
  • SQL Injection
  • Session Hijacking
  • Cross-Site Request Forgery (CSRF)
  • Cross-Site Scripting (XSS)
  • Buffer Overflow

Attack Methodology

Information Gathering

Collecting information from internet.

robots.txt

Attacker extract information about internal files.

Read more

Web Server Footprinting

Results the server name, type, OS, applications, etc.

Tools:

  • Netcraft
  • Maltego
  • httprecon

Mirroring a website

Download the website, to inspect offline, without any interaction to the target.

Tool:

  • httrack

Vulnerability Scanning

Automated tool to inspect website and detect vulnerabilities. These tools perform depp inspection of scripts, open ports, banners, etc.

Tools:

  • owasp-zap
  • openvas

Hacking Web Passwords

Extract passwords to gain authorized access to the system. Password may be get from social engineering, tampering the communication, etc.

Password Attacks classification:

  • Non-Electronic attacks
  • Active online attacks
  • Passive online attacks
  • Default password
  • offline attack

Countermeasures

  • Place web server in a secure zone (behind firewall, IDS, IPS, DMZ)
  • Detect potential changes (hashing, script to detect change)
  • Auditing ports
  • Disable insecure and unnecessary ports
  • Using port 443 (HTTPS) over port 80 (HTTP)
  • Encrypted traffic
  • Server certificate
  • Code Access Security Policy
  • Disable tracing
  • Disable debug complies
  • Software update
  • Disable default account

Patch Management

Hotfix is a small update which fix an issue. Patch is a bigger of software to fix one or more issues.

Methods:

  • Manual download
  • Auto-Update

Patch Management is an automated process to detect missing security patches, find out solutions, download patch, test the patch in an isolated environment then deploy the patch onto the systems.

Tools:

  • Microsoft Baseline Security Analyzer (MBSA)