Pros of ModSecurity

• More comprehensive web application firewall (WAF) solution
• Offers broader protection against various web attacks
• Highly configurable and customizable

Cons of ModSecurity

• Steeper learning curve and more complex setup
• Can be resource-intensive, potentially impacting server performance
• Requires more maintenance and fine-tuning

Code Comparison

ModSecurity rule example:

SecRule REQUEST_HEADERS:User-Agent "nikto" \
    "id:1000,phase:1,deny,log,msg:'Nikto Scan Detected'"

CoreRuleSet rule example:

SecRule REQUEST_HEADERS:User-Agent "@contains nikto" \
    "id:900001,phase:1,block,t:lowercase,log,msg:'Nikto Scan Detected'"

Both examples show rules to detect and block Nikto scans. ModSecurity's rule is more basic, while CoreRuleSet's rule includes additional options like case-insensitive matching.

CoreRuleSet is a set of rules designed to work with ModSecurity, providing pre-configured protection against common web application attacks. It's easier to implement but less flexible than a full ModSecurity setup. CoreRuleSet is ideal for users who want quick, out-of-the-box protection, while ModSecurity is better for those needing granular control and customization of their WAF.

Pros of Naxsi

• Lightweight and designed specifically for Nginx, offering better performance
• Simple configuration and easy to deploy
• Focuses on positive security model, potentially reducing false positives

Cons of Naxsi

• Smaller rule set compared to CoreRuleSet, potentially offering less comprehensive protection
• Less frequent updates and smaller community support
• Limited documentation and learning resources

Code Comparison

Naxsi rule example:

MainRule "str:select" "msg:SQL Injection" "mz:BODY|URL|ARGS|$HEADERS_VAR:Cookie" "s:$SQL:4" id:1000;

CoreRuleSet rule example:

SecRule REQUEST_COOKIES|!REQUEST_COOKIES:/__utm/|REQUEST_COOKIES_NAMES|ARGS_NAMES|ARGS|XML:/* "@rx select.+(?:from|union.+select)" \
    "id:942100,\
    phase:2,\
    block,\
    capture,\
    t:none,t:urlDecodeUni,t:sqlHexDecode,\
    msg:'SQL Injection Attack Detected via libinjection',\
    logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\
    tag:'application-multi',\
    tag:'language-multi',\
    tag:'platform-multi',\
    tag:'attack-sqli',\
    tag:'OWASP_CRS',\
    tag:'OWASP_CRS/WEB_ATTACK/SQL_INJECTION',\
    tag:'WASCTC/WASC-19',\
    tag:'OWASP_TOP_10/A1',\
    tag:'OWASP_AppSensor/CIE1',\
    tag:'PCI/6.5.2',\
    ver:'OWASP_CRS/3.2.0',\
    severity:'CRITICAL',\
    setvar:'tx.sql_injection_score=+%{tx.critical_anomaly_score}',\
    setvar:'tx.anomaly_score_pl1=+%{tx.critical_anomaly_score}'"

Pros of lua-resty-waf

• Written in Lua, offering better performance and lower resource usage
• Designed specifically for OpenResty, allowing seamless integration
• More flexible and customizable due to its modular architecture

Cons of lua-resty-waf

• Smaller community and less frequent updates compared to coreruleset
• Fewer out-of-the-box rules, requiring more manual configuration
• Limited documentation and examples for advanced use cases

Code Comparison

lua-resty-waf:

local waf = require "resty.waf"
local waf_instance = waf:new()
waf_instance:exec()

coreruleset:

SecRule REQUEST_HEADERS:User-Agent "@rx (?i)(?:acunetix|arachni|nikto|w3af)" \
    "id:900000,\
    phase:1,\
    block,\
    t:none,\
    msg:'Scanner Detection',\
    logdata:'%{MATCHED_VAR}',\
    tag:'application-attack-reconnaissance',\
    severity:'CRITICAL'"

The lua-resty-waf code snippet demonstrates its simplicity in implementation, while the coreruleset example showcases its more detailed and comprehensive rule definition approach.

Pros of Suricata

• Full-featured network security monitoring engine with intrusion detection and prevention capabilities
• Supports hardware acceleration for improved performance on high-speed networks
• Extensive protocol support and ability to analyze encrypted traffic

Cons of Suricata

• More complex setup and configuration compared to CoreRuleSet
• Higher system resource requirements for full functionality
• Steeper learning curve for effective rule creation and management

Code Comparison

Suricata rule example:

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"Possible SQL Injection"; flow:established,to_server; content:"SELECT"; http_uri; pcre:"/SELECT.+FROM/i"; sid:1000001; rev:1;)

CoreRuleSet rule example:

SecRule REQUEST_URI "@rx SELECT.+FROM" \
    "id:942100,\
    phase:2,\
    block,\
    capture,\
    t:none,t:urlDecodeUni,\
    msg:'SQL Injection Attack Detected via libinjection',\
    logdata:'Matched Data: %{TX.0} found within %{MATCHED_VAR_NAME}: %{MATCHED_VAR}',\
    tag:'application-multi',\
    tag:'language-multi',\
    tag:'platform-multi',\
    tag:'attack-sqli',\
    tag:'OWASP_CRS',\
    tag:'OWASP_CRS/WEB_ATTACK/SQL_INJECTION',\
    tag:'WASCTC/WASC-19',\
    tag:'OWASP_TOP_10/A1',\
    tag:'OWASP_AppSensor/CIE1',\
    tag:'PCI/6.5.2',\
    ver:'OWASP_CRS/3.2.0',\
    severity:'CRITICAL',\
    setvar:'tx.sql_injection_score=+%{tx.critical_anomaly_score}',\
    setvar:'tx.anomaly_score_pl1=+%{tx.critical_anomaly_score}'"

Pros of fail2ban

• Lightweight and easy to set up, focusing on intrusion prevention
• Highly customizable with flexible configuration options
• Can protect various services beyond just web applications

Cons of fail2ban

• Primarily focused on IP-based blocking, which may not be as effective against sophisticated attacks
• Requires more manual configuration and maintenance compared to CoreRuleSet
• May cause false positives if not properly configured

Code Comparison

fail2ban configuration example:

[sshd]
enabled = true
port = ssh
filter = sshd
logpath = /var/log/auth.log
maxretry = 3

CoreRuleSet rule example:

SecRule REQUEST_HEADERS:User-Agent "@rx (?i)(?:acunetix|nikto|sqlmap)" \
    "id:900001,\
    phase:1,\
    block,\
    t:none,\
    msg:'Malicious User Agent',\
    severity:'CRITICAL'"

While fail2ban focuses on log parsing and IP blocking, CoreRuleSet provides more granular HTTP request inspection and rule-based protection. fail2ban is better suited for general intrusion prevention across multiple services, while CoreRuleSet excels at web application security with its extensive rule set and integration with web application firewalls.