CVE-2025-29519
📋 TL;DR
A command injection vulnerability in D-Link DSL-7740C routers allows attackers to execute arbitrary commands via crafted GET requests targeting the EXE parameter. This affects users of DSL-7740C routers with vulnerable firmware versions, potentially compromising the device and connected networks.
💻 Affected Systems
- D-Link DSL-7740C
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise leading to router takeover, credential theft, network traffic interception, and lateral movement to connected devices.
Likely Case
Router compromise enabling DNS hijacking, credential harvesting, or botnet recruitment for DDoS attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Exploitation requires sending crafted GET requests to the vulnerable EXE parameter. No authentication needed based on description.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check D-Link advisory for latest patched firmware
Vendor Advisory: https://www.dlink.com/en/security-bulletin/
Restart Required: Yes
Instructions:
1. Visit D-Link support site. 2. Download latest firmware for DSL-7740C. 3. Log into router admin interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router after update completes.
🔧 Temporary Workarounds
Disable TR069 WAN Access
linuxBlock external access to TR069 management interface on WAN interface
iptables -A INPUT -p tcp --dport 7547 -j DROP
iptables -A INPUT -p udp --dport 7547 -j DROP
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Place router behind firewall with strict inbound rules blocking port 7547 and other management ports
- Disable TR069 remote management feature in router configuration if not needed
🔍 How to Verify
Check if Vulnerable:
Check if router responds to crafted GET requests on TR069 interface (port 7547) with command injection payloads in EXE parameterCheck Version:
Login to router admin interface and check firmware version in System Status or Maintenance sectionVerify Fix Applied:
Verify firmware version is newer than vulnerable version and test that command injection attempts no longer succeed📡 Detection & Monitoring
Log Indicators:
- Unusual GET requests to TR069 interface with shell metacharacters in parameters
- Failed command execution attempts in system logs
- Unexpected process execution from web interface
Network Indicators:
- HTTP requests to port 7547 with suspicious parameters containing ;, |, &, or $() characters
- Outbound connections from router to unexpected destinations
SIEM Query:
source="router_logs" AND (uri="*EXE=*" AND (uri="*;*" OR uri="*|*" OR uri="*&*" OR uri="*$(*"))