CVE-2021-46457
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary commands on D-Link DIR-823-Pro routers via command injection in the samba_name parameter. Attackers can gain full control of affected devices, potentially compromising network security. Only D-Link DIR-823-Pro v1.0.2 devices are affected.
💻 Affected Systems
- D-Link DIR-823-Pro
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover allowing attackers to install persistent malware, pivot to internal networks, intercept all network traffic, and use the device as part of a botnet.
Likely Case
Attackers gain remote shell access to modify device settings, steal credentials, and use the device for further attacks on the internal network.
If Mitigated
With proper network segmentation and access controls, impact is limited to the isolated device with no lateral movement possible.
🎯 Exploit Status
Exploitation requires authentication to the web interface. Public proof-of-concept code exists in GitHub repositories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.0.2B05 or later
Vendor Advisory: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10285
Restart Required: Yes
Instructions:
1. Log into D-Link support portal. 2. Download firmware v1.0.2B05 or later. 3. Access router web interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and install new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Samba Service
allTurn off the vulnerable Samba service to prevent exploitation
Access web interface > USB Settings > Samba > Disable
Restrict Web Interface Access
allLimit access to the management interface to trusted IPs only
Access web interface > Firewall > Access Control > Add trusted IP ranges
🧯 If You Can't Patch
- Isolate affected devices in a separate VLAN with strict firewall rules
- Implement network monitoring for unusual outbound connections from the router
🔍 How to Verify
Check if Vulnerable:
Check firmware version in web interface: System Tools > Firmware. If version is exactly v1.0.2, device is vulnerable.Check Version:
Not applicable - use web interfaceVerify Fix Applied:
Verify firmware version is v1.0.2B05 or later in System Tools > Firmware.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed authentication attempts followed by successful login
- Samba configuration changes from unusual IPs
Network Indicators:
- Outbound connections from router to suspicious IPs
- Unusual port scanning originating from router
- DNS queries to known malicious domains from router
SIEM Query:
source="router_logs" AND ("ChgSambaUserSettings" OR "samba_name") AND command="*"🔗 References
- https://github.com/pjqwudi/my_vuln/blob/main/D-link/vuln_23/23.md
- https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10285
- https://www.dlink.com/en/security-bulletin/
- https://github.com/pjqwudi/my_vuln/blob/main/D-link/vuln_23/23.md
- https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10285
- https://www.dlink.com/en/security-bulletin/
