CVE-2012-10021
📋 TL;DR
This CVE describes a critical stack-based buffer overflow vulnerability in D-Link DIR-605L routers that allows remote unauthenticated attackers to execute arbitrary code with root privileges. The vulnerability affects firmware versions 1.12 and 1.13 through unsafe string handling in the CAPTCHA authentication mechanism. Anyone using affected D-Link DIR-605L routers with vulnerable firmware is at risk.
💻 Affected Systems
- D-Link DIR-605L Wireless N300 Cloud Router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attacker to install persistent malware, intercept all network traffic, pivot to internal networks, and use device as botnet node.
Likely Case
Remote code execution leading to device takeover, credential theft, and network surveillance.
If Mitigated
Limited impact if device is behind firewall with no internet exposure and strict network segmentation.
🎯 Exploit Status
Metasploit module available, multiple public exploit scripts exist, exploitation is straightforward for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware version 1.14 or later
Vendor Advisory: https://forums.dlink.com/index.php?topic=51923.0
Restart Required: Yes
Instructions:
1. Download latest firmware from D-Link support site. 2. Log into router admin interface. 3. Navigate to Tools > Firmware. 4. Upload and install new firmware. 5. Wait for automatic reboot.
🔧 Temporary Workarounds
Disable remote administration
allPrevent external access to router web interface
Network segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected router with newer model or different vendor
- Place router behind firewall with strict inbound rules blocking all access to port 80/443
🔍 How to Verify
Check if Vulnerable:
Check router web interface > Tools > Firmware for version number. If version is 1.12 or 1.13, device is vulnerable.Check Version:
curl -s http://router-ip/ | grep -i firmware or check web interface directlyVerify Fix Applied:
After firmware update, verify version shows 1.14 or higher in router admin interface.📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts with malformed CAPTCHA data
- Unusual POST requests to /goform/formLogin with long FILECODE parameter
Network Indicators:
- Exploit traffic patterns matching Metasploit module signatures
- Shellcode delivery to router IP
SIEM Query:
source="router-logs" AND (uri="/goform/formLogin" AND (param="FILECODE" AND length>100))🔗 References
- https://forums.dlink.com/index.php?topic=51923.0
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/linux/http/dlink_dir605l_captcha_bof.rb
- https://web.archive.org/web/20121012062554/http://www.devttys0.com/2012/10/exploiting-a-mips-stack-overflow/
- https://www.exploit-db.com/exploits/29127
- https://www.vulncheck.com/advisories/dlink-dir605l-captcha-handling-stack-based-buffer-overflow
