NetScaler WAF Signatures Update v137

NetScaler has released a new version of its integrated Web App Firewall signatures to help customers mitigate several CVEs with varying CVSS scores. 

CVE-2024-5932: “GiveWP” by StellarWP is a WordPress plugin widely used for donation and fundraising management. With over 100,000 active installations, the plugin is susceptible to PHP Object Injection via in all versions up to, and including, 3.14.1. The issue affects the “donation form” because the plugin does not validate serialized input in the “give_title” parameter field. Unauthenticated attackers can exploit this weakness to execute arbitrary commands on the server, potentially resulting in complete site takeover or data destruction.

CVE-2024-6172: Email Subscribers” by Icegram Express is a WordPress plugin widely used for email marketing, subscriber list management, and newsletter distribution. With over 80,000 active installations, the plugin is susceptible to time-based SQL Injection via the “db” parameter in all versions up to, and including, 5.7.25. Unauthenticated attackers can exploit this weakness by injecting malicious SQL code, potentially granting access to sensitive information stored in the database.

 Signatures included in v137:

NetScaler customers can quickly import the above signatures to help reduce risk and lower exposure associated with these vulnerabilities. Signatures are compatible with NetScaler (formerly Citrix ADC) software version 11.1, 12.0, 12.1, 13.0 and 13.1. NOTE: Software versions 11.1 and 12.0 are end of life, and you should consider upgrading for continued support. Learn more about the NetScaler software release lifecycle.

If you are already using NetScaler Web App Firewall with the signature auto-update feature enabled, verify that your signature file version is 137 or later and then follow these steps.

1. Search your signatures for <number>
2. Select the results with ID 
3. Choose “Enable Rules” and click OK

NetScaler WAF Best Practices

NetScaler recommends that WAF users always download the latest signature version, enable signature auto-update, and subscribe to receive signature alert notifications. NetScaler will continue to monitor this dynamic situation and provide updates as new mitigations become available.

Handling false positives

If app availability is affected by false positives that result from the above mitigation policies, relaxations can be applied. NetScaler recommends the following modifications to the policy.

Modifications to NetScaler Web App Firewall Policy:

add policy patset exception_list

# (Example: bind policy patset exception_list “/exception_url”) 

Prepend the existing WAF policy with:

HTTP.REQ.URL.CONTAINS_ANY(“exception_list”).NOT

# (Example :  set appfw policy my_WAF_policy q^HTTP.REQ.URL.CONTAINS_ANY(“exception_list”).NOT && <existing rule>^

NOTE: Any endpoint covered by the exception_list may expose those assets to risks 

Additional Information

NetScaler Web App Firewall benefits from a single code base across all its form-factors (physical, virtual, bare-metal, and containers). This signature update applies to all form factors and deployment models of NetScaler Web App Firewall.

Learn more about NetScaler Web app Firewall. Read our alert articles and bot signature articles to learn more about NetScaler WAF signatures, and find out how you can receive signature alert notifications.

Please join the NetScaler Community today and engage with your peers to learn more about how they are protecting their businesses with NetScaler WAF.