CVE-2021-3160
📋 TL;DR
CVE-2021-3160 is an unauthenticated remote code execution vulnerability in ASSUWEB 359.3 build 1, a subcomponent of ACA ASSUREX RENTES insurance contract management software. Attackers can exploit insecure Java deserialization in the login page via crafted HTTP requests to execute arbitrary code on the server. Organizations using affected versions of ACA ASSUREX RENTES are at risk.
💻 Affected Systems
- ACA ASSUREX RENTES
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install malware, steal sensitive data, pivot to internal networks, and maintain persistent access.
Likely Case
Unauthenticated attackers gain remote code execution, potentially leading to data theft, ransomware deployment, or system takeover.
If Mitigated
With proper network segmentation and monitoring, impact may be limited to the affected application server, though code execution still occurs.
🎯 Exploit Status
Exploitation requires sending specially crafted HTTP requests to the login page. Public advisories contain technical details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Contact vendor for patched version
Vendor Advisory: https://www.aca.fr/solution/assurex-solution-gestion-des-contrats-assurance/
Restart Required: Yes
Instructions:
1. Contact ACA for patched version. 2. Apply patch to affected ASSUWEB component. 3. Restart application services. 4. Verify fix implementation.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to ASSUWEB login page to trusted IP addresses only
Use firewall rules to limit access to ASSUWEB port (typically 8080/8443) to authorized networks
Web Application Firewall
allDeploy WAF with rules to block Java deserialization attacks
Configure WAF to inspect HTTP requests for Java serialized object patterns and block malicious payloads
🧯 If You Can't Patch
- Isolate affected systems in separate network segments with strict access controls
- Implement application-level monitoring for suspicious login page activity and Java deserialization attempts
🔍 How to Verify
Check if Vulnerable:
Check ASSUWEB version in application interface or configuration files. Version 359.3 build 1 is vulnerable.Check Version:
Check application.properties or web interface for ASSUWEB version informationVerify Fix Applied:
Verify with vendor that patched version is installed and test that crafted serialized objects no longer execute.📡 Detection & Monitoring
Log Indicators:
- Unusual Java deserialization errors in application logs
- Multiple failed login attempts with unusual payloads
- Unexpected process execution from web server
Network Indicators:
- HTTP POST requests to login page containing serialized Java objects
- Unusual outbound connections from application server
SIEM Query:
source="*assuweb*" AND (message="*deserialization*" OR message="*ObjectInputStream*" OR status=500 AND uri="/login")🔗 References
- https://www.aca.fr/solution/assurex-solution-gestion-des-contrats-assurance/
- https://www.digital.security/fr/sites/default/files/advisories/cert-ds_advisory_cve-2021-3160.txt
- https://www.aca.fr/solution/assurex-solution-gestion-des-contrats-assurance/
- https://www.digital.security/fr/sites/default/files/advisories/cert-ds_advisory_cve-2021-3160.txt
