CVE-2023-4882
📋 TL;DR
This CVE describes a denial-of-service vulnerability in Open5GS where an attacker can register a new Virtual Network Function (VNF) value that triggers execution of the args-abort.c file, causing the service to crash. This affects Open5GS deployments, particularly those with exposed management interfaces. The vulnerability allows unauthenticated attackers to disrupt service availability.
💻 Affected Systems
- Open5GS
📦 What is this software?
Open5gs by Open5gs
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage of Open5GS components, disrupting mobile network services including voice, data, and signaling for affected subscribers.
Likely Case
Service disruption of specific Open5GS components, requiring manual restart and causing temporary service degradation.
If Mitigated
Limited impact with proper network segmentation and access controls preventing unauthorized access to vulnerable interfaces.
🎯 Exploit Status
The vulnerability appears straightforward to exploit by sending a crafted VNF registration request. No authentication is required based on the description.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in provided references, but patches are available according to INCIBE advisory
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-open5gs
Restart Required: Yes
Instructions:
1. Check the INCIBE advisory for specific patch information. 2. Update Open5GS to the latest patched version. 3. Restart all Open5GS services. 4. Verify the fix by testing VNF registration functionality.
🔧 Temporary Workarounds
Network Access Control
linuxRestrict access to Open5GS management interfaces to trusted networks only
iptables -A INPUT -p tcp --dport [Open5GS-port] -s [trusted-network] -j ACCEPT
iptables -A INPUT -p tcp --dport [Open5GS-port] -j DROP
Disable VNF Registration
allTemporarily disable VNF registration functionality if not required
# Edit Open5GS configuration to disable VNF registration features
# Consult Open5GS documentation for specific configuration parameters
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Open5GS management interfaces
- Deploy Web Application Firewall (WAF) rules to block malicious VNF registration attempts
🔍 How to Verify
Check if Vulnerable:
Check Open5GS version and compare with patched versions mentioned in the INCIBE advisory. Test by attempting VNF registration and monitoring for service crashes.Check Version:
open5gs --version or check Open5GS configuration/installation documentationVerify Fix Applied:
After patching, attempt to trigger the vulnerability by sending VNF registration requests and verify the service remains stable. Check that args-abort.c is not executed.📡 Detection & Monitoring
Log Indicators:
- Unexpected VNF registration attempts
- Service crash logs mentioning args-abort.c or arg-log.php
- Abnormal process termination of Open5GS components
Network Indicators:
- Unusual traffic to Open5GS management ports from untrusted sources
- Patterns of VNF registration requests followed by service unavailability
SIEM Query:
source="open5gs.log" AND ("VNF registration" OR "args-abort" OR "service crash")