CVE-2025-29522
📋 TL;DR
This CVE describes a command injection vulnerability in D-Link DSL-7740C routers that allows authenticated attackers to execute arbitrary commands via the ping function. The vulnerability affects users of this specific router model with vulnerable firmware. Successful exploitation could lead to complete device compromise.
💻 Affected Systems
- D-Link DSL-7740C
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full router compromise allowing attacker to intercept traffic, modify configurations, pivot to internal networks, or install persistent malware.
Likely Case
Router takeover enabling network reconnaissance, DNS hijacking, or credential theft from connected devices.
If Mitigated
Limited impact if proper network segmentation and access controls prevent lateral movement from the router.
🎯 Exploit Status
Requires authentication but command injection is straightforward once authenticated. No public exploit code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check D-Link for latest 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 web interface. 4. Navigate to System Tools > Firmware Upgrade. 5. Upload and apply new firmware. 6. Router will reboot automatically.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Change default credentials
allUse strong, unique password for router admin account
🧯 If You Can't Patch
- Segment router on isolated network segment
- Implement strict firewall rules limiting router management access to trusted IPs only
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under Status > Device InfoCheck Version:
Login to router web interface and check Status > Device Info pageVerify Fix Applied:
Verify firmware version is newer than DSL7740C.V6.TR069.20211230📡 Detection & Monitoring
Log Indicators:
- Unusual ping commands in router logs
- Multiple failed login attempts followed by ping activity
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains from router
SIEM Query:
source="router" AND (event="ping" AND command="*;*" OR command="*|*" OR command="*`*")