CVE-2025-15532
📋 TL;DR
CVE-2025-15532 is a resource consumption vulnerability in Open5GS's Timer Handler component that allows remote attackers to cause denial of service through resource exhaustion. This affects all Open5GS deployments up to version 2.7.5, particularly those exposed to untrusted networks.
💻 Affected Systems
- Open5GS
📦 What is this software?
Open5gs by Open5gs
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption of Open5GS components, potentially affecting mobile network functionality for all connected users.
Likely Case
Degraded performance or temporary service unavailability for affected Open5GS instances.
If Mitigated
Minimal impact with proper network segmentation and resource monitoring in place.
🎯 Exploit Status
Exploit code is publicly available and remote exploitation requires no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit c7c131f8d2cb1195ada5e0e691b6868ebcd8a845
Vendor Advisory: https://github.com/open5gs/open5gs/commit/c7c131f8d2cb1195ada5e0e691b6868ebcd8a845
Restart Required: Yes
Instructions:
1. Update Open5GS to version after 2.7.5 or apply commit c7c131f8d2cb1195ada5e0e691b6868ebcd8a845. 2. Restart all Open5GS services. 3. Verify the patch is applied by checking the commit hash.
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict network access to Open5GS instances to trusted sources only
iptables -A INPUT -p tcp --dport [Open5GS_PORT] -s [TRUSTED_IP] -j ACCEPT
iptables -A INPUT -p tcp --dport [Open5GS_PORT] -j DROP
Resource Limits
linuxImplement system resource limits to prevent complete exhaustion
ulimit -n 4096
systemctl set-property open5gs.service MemoryLimit=2G
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Deploy monitoring for resource consumption anomalies and implement automated restart policies
🔍 How to Verify
Check if Vulnerable:
Check Open5GS version: open5gs --version | grep '2.7.5' or earlierCheck Version:
open5gs --versionVerify Fix Applied:
Verify commit hash contains c7c131f8d2cb1195ada5e0e691b6868ebcd8a845: git log --oneline | grep c7c131f8📡 Detection & Monitoring
Log Indicators:
- Unusual timer handler activity
- Resource exhaustion warnings
- Service restart patterns
Network Indicators:
- High volume of requests to timer-related endpoints
- Unusual traffic patterns from single sources
SIEM Query:
source="open5gs.log" AND ("resource exhaustion" OR "timer handler" OR "denial of service")🔗 References
- https://github.com/open5gs/open5gs/
- https://github.com/open5gs/open5gs/commit/c7c131f8d2cb1195ada5e0e691b6868ebcd8a845
- https://github.com/open5gs/open5gs/issues/4220
- https://github.com/open5gs/open5gs/issues/4220#issue-3766066853
- https://github.com/open5gs/open5gs/issues/4221
- https://vuldb.com/?ctiid.341599
- https://vuldb.com/?id.341599
- https://vuldb.com/?submit.729354
- https://vuldb.com/?submit.729357
- https://vuldb.com/?submit.735340
- https://vuldb.com/?submit.735341
- https://vuldb.com/?submit.735342
