CVE-2025-29635
📋 TL;DR
A command injection vulnerability in D-Link DIR-823X routers allows authenticated attackers to execute arbitrary commands on affected devices by sending specially crafted POST requests to the /goform/set_prohibiting endpoint. This affects users of DIR-823X routers with firmware versions 240126 and 240802, potentially giving attackers full control over the device.
💻 Affected Systems
- D-Link DIR-823X
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, or use the device as part of a botnet.
Likely Case
Attackers gain shell access to modify router settings, steal credentials, or deploy cryptocurrency miners on vulnerable devices.
If Mitigated
Limited impact if network segmentation isolates the router and strong authentication controls prevent unauthorized access.
🎯 Exploit Status
Exploit requires authentication but is well-documented in public GitHub repository with proof-of-concept details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check D-Link security advisories for latest patched firmware
Vendor Advisory: Monitor D-Link security advisories page for official response
Restart Required: Yes
Instructions:
1. Log into router admin interface. 2. Navigate to firmware update section. 3. Download latest firmware from D-Link support site. 4. Upload and apply firmware update. 5. Reboot router after update completes.
🔧 Temporary Workarounds
Disable remote administration
allPrevent external access to router administration interface
Change default credentials
allUse strong, unique passwords for router administration
🧯 If You Can't Patch
- Isolate router on separate VLAN with strict firewall rules
- Implement network monitoring for suspicious POST requests to /goform/set_prohibiting
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is 240126 or 240802, device is vulnerable.Check Version:
Check router web interface at System > Firmware or via SSH if enabled: cat /etc/versionVerify Fix Applied:
After updating firmware, verify version number has changed from vulnerable versions and test that POST requests to /goform/set_prohibiting with command injection payloads no longer execute.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/set_prohibiting
- Commands containing shell metacharacters in request parameters
- Multiple failed authentication attempts followed by successful login
Network Indicators:
- HTTP POST requests to router IP on port 80/443 with /goform/set_prohibiting path
- Unusual outbound connections from router to external IPs
SIEM Query:
source="router_logs" AND (uri_path="/goform/set_prohibiting" OR command="*;*" OR command="*|*" OR command="*`*" OR command="*$(*")