CVE-2025-53512
📋 TL;DR
This vulnerability allows unauthorized users to access the /log endpoint on Juju controllers, exposing debug messages that may contain sensitive information. Anyone running vulnerable Juju controller versions is affected, particularly those with internet-facing deployments.
💻 Affected Systems
- Juju Controller
📦 What is this software?
Juju by Canonical
Juju by Canonical
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain access to sensitive debug information including credentials, configuration details, or internal system data, leading to further compromise of the Juju environment.
Likely Case
Unauthorized users access debug logs containing operational information, potentially revealing system architecture or configuration details that could aid in further attacks.
If Mitigated
With proper network segmentation and authentication controls, impact is limited to authorized users only accessing their own debug information.
🎯 Exploit Status
Exploitation requires network access to the controller's /log endpoint. No authentication bypass needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check the GitHub advisory for specific fixed versions
Vendor Advisory: https://github.com/juju/juju/security/advisories/GHSA-r64v-82fh-xc63
Restart Required: Yes
Instructions:
1. Update Juju controller to the latest patched version. 2. Restart the Juju controller service. 3. Verify the fix by testing access to /log endpoint.
🔧 Temporary Workarounds
Network Access Restriction
linuxRestrict network access to the Juju controller's /log endpoint using firewall rules
# Example iptables rule to block external access to port 17070
sudo iptables -A INPUT -p tcp --dport 17070 -s ! 10.0.0.0/8 -j DROP
Reverse Proxy Authentication
linuxPlace Juju controller behind a reverse proxy with authentication requirements
# Configure nginx with basic auth
location /log {
auth_basic "Restricted";
auth_basic_user_file /etc/nginx/.htpasswd;
proxy_pass http://juju-controller:17070;
}
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Juju controllers from untrusted networks
- Deploy a web application firewall (WAF) in front of Juju controllers to block unauthorized /log endpoint access
🔍 How to Verify
Check if Vulnerable:
Attempt to access http://<controller-ip>:17070/log without authentication. If you can access debug logs, the system is vulnerable.Check Version:
juju versionVerify Fix Applied:
After patching, attempt to access the /log endpoint without authentication. Access should be denied or redirected to authentication.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to /log endpoint
- Multiple failed authentication attempts followed by successful /log access
Network Indicators:
- Unusual traffic patterns to controller port 17070 from unauthorized IPs
- HTTP GET requests to /log endpoint without authentication headers
SIEM Query:
source="juju-controller" AND (uri_path="/log" AND NOT auth_success="true")