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How the CVE Works:
The vulnerability in Apereo CAS 5.2.6 stems from improper input validation in the `saveService` function of the Groovy Code Handler component. Attackers can inject malicious Groovy scripts via crafted HTTP requests, which are then executed on the server due to unsafe deserialization. This allows remote code execution (RCE) under the context of the CAS service account. The complexity is high due to the need for precise payload crafting, but successful exploitation can lead to full system compromise.
DailyCVE Form:
Platform: Apereo CAS
Version: <= 5.2.6
Vulnerability: Code Injection
Severity: Critical
Date: Apr 27, 2025
What Undercode Say:
Exploitation:
1. Payload Crafting:
println "hostname".execute().text
2. Curl Exploit:
curl -X POST -d "groovyScript=maliciousCode" http://target/cas-management/saveService
3. Metasploit Module:
exploit/multi/http/apereo_cas_groovy_rce
Protection:
1. Input Sanitization:
if (script.contains("execute")) { throw new SecurityException(); }
2. WAF Rules:
location ~ /saveService { deny all; }
3. Patch Workaround:
Disable Groovy script support in `cas-management-webapp-support`.
Detection:
1. Log Analysis:
grep "groovyScript" /var/log/cas/audit.log
2. IDS Signature:
alert http any any -> any 8080 (msg:"CAS Groovy Injection"; content:"groovyScript="; sid:10001;)
Mitigation:
- Upgrade to a non-vulnerable version (if patched).
- Restrict network access to CAS management interfaces.
- Audit all Groovy scripts in deployment.
Forensics:
strings /proc/<CAS_PID>/environ | grep -i groovy
References:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
