CVE-2023-38319
📋 TL;DR
CVE-2023-38319 is a command injection vulnerability in OpenNDS that allows attackers with access to the configuration file to execute arbitrary operating system commands. This affects OpenNDS installations before version 10.1.3, potentially compromising the entire system where OpenNDS runs. Organizations using OpenNDS for captive portal functionality are at risk.
💻 Affected Systems
- OpenNDS
📦 What is this software?
Opennds by Opennds
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attackers to execute arbitrary commands with the privileges of the OpenNDS process, potentially leading to complete system takeover, data exfiltration, or lateral movement within the network.
Likely Case
Attackers with access to the configuration file (either directly or through other vulnerabilities) can execute commands to install malware, create backdoors, or disrupt network services.
If Mitigated
With proper file permissions and network segmentation, impact is limited to the OpenNDS service and its host system, preventing lateral movement to other systems.
🎯 Exploit Status
Exploitation requires access to the configuration file, which may be obtained through other vulnerabilities or misconfigurations. The command injection itself is straightforward once file access is achieved.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.3
Vendor Advisory: https://github.com/openNDS/openNDS/releases/tag/v10.1.3
Restart Required: Yes
Instructions:
1. Download OpenNDS version 10.1.3 or later from the official repository. 2. Stop the OpenNDS service. 3. Backup current configuration. 4. Install the new version. 5. Restart the OpenNDS service.
🔧 Temporary Workarounds
Restrict configuration file permissions
linuxSet strict file permissions on OpenNDS configuration files to prevent unauthorized access
chmod 600 /etc/opennds/*.conf
chown root:root /etc/opennds/*.conf
Network segmentation
allIsolate OpenNDS systems from critical network segments
🧯 If You Can't Patch
- Implement strict file permissions on all OpenNDS configuration files (chmod 600)
- Monitor configuration files for unauthorized modifications and restrict access to authorized administrators only
🔍 How to Verify
Check if Vulnerable:
Check OpenNDS version with 'opennds --version' or examine package version. If version is below 10.1.3, the system is vulnerable.Check Version:
opennds --versionVerify Fix Applied:
After patching, verify version is 10.1.3 or higher with 'opennds --version'. Test configuration file access restrictions.📡 Detection & Monitoring
Log Indicators:
- Unusual process execution from OpenNDS context
- Modifications to OpenNDS configuration files
- Failed attempts to access configuration files
Network Indicators:
- Unexpected outbound connections from OpenNDS host
- Unusual network traffic patterns from captive portal systems
SIEM Query:
process.name:sh OR process.name:bash AND parent.name:opennds🔗 References
- https://github.com/openNDS/openNDS/blob/master/ChangeLog
- https://github.com/openNDS/openNDS/releases/tag/v10.1.3
- https://openwrt.org/docs/guide-user/services/captive-portal/opennds
- https://www.forescout.com/resources/sierra21-vulnerabilities
- https://github.com/openNDS/openNDS/blob/master/ChangeLog
- https://github.com/openNDS/openNDS/releases/tag/v10.1.3
- https://openwrt.org/docs/guide-user/services/captive-portal/opennds
- https://www.forescout.com/resources/sierra21-vulnerabilities
