CVE-2025-57636
📋 TL;DR
This CVE describes an OS command injection vulnerability in D-Link C1 routers where an attacker can execute arbitrary commands via the HTTP 'time' parameter. The vulnerability exists in the jhttpd web server component and affects D-Link C1 router users. Successful exploitation could lead to complete device compromise.
💻 Affected Systems
- D-Link C1 Router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full router compromise allowing attacker to intercept traffic, modify configurations, install persistent backdoors, pivot to internal networks, or brick the device.
Likely Case
Attacker gains shell access to execute commands, potentially stealing credentials, modifying DNS settings, or launching attacks against internal devices.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Exploitation requires sending crafted HTTP requests with malicious time parameter. No public exploit code available but vulnerability details are documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check D-Link security bulletin for latest patched firmware
Vendor Advisory: https://www.dlink.com/en/security-bulletin/
Restart Required: Yes
Instructions:
1. Visit D-Link support website 2. Download latest firmware for C1 router 3. Log into router admin interface 4. Navigate to firmware update section 5. Upload and apply new firmware 6. Wait for router to reboot
🔧 Temporary Workarounds
Disable Remote Management
allPrevents external attackers from accessing the vulnerable web interface
Network Segmentation
allIsolate router management interface to trusted network segment only
🧯 If You Can't Patch
- Place router behind firewall with strict inbound rules blocking all WAN access to management interface
- Implement network monitoring for unusual HTTP requests containing command injection patterns
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is 2020-02-21, device is vulnerable.Check Version:
Log into router web interface and navigate to System Status or Firmware Information pageVerify Fix Applied:
After updating firmware, verify version has changed from 2020-02-21 to a newer patched version.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to router with 'time' parameter containing shell metacharacters
- Failed authentication attempts followed by command injection attempts
Network Indicators:
- HTTP requests containing shell commands in parameters
- Unusual outbound connections from router to external IPs
SIEM Query:
http.method:POST AND http.uri_path:* AND http.param.time:* AND (http.param.time:*|* OR http.param.time:*;* OR http.param.time:*`*)