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How the CVE Works:
The vulnerability CVE-2025-13549 is a stack-based buffer overflow in the D-Link DIR-822K router’s firmware version 1.00. It occurs in the function sub_455524 within the /boafrm/formNtp file, which handles NTP configuration submissions via the web interface. When processing HTTP POST requests, the “submit-url” parameter is passed to this function without proper bounds checking. An attacker can craft a malicious request with an excessively long submit-url value, exceeding the fixed buffer size on the stack. This overflow corrupts adjacent memory, including the return address or function pointers. By precisely controlling the overflow data, an attacker can overwrite these addresses to redirect execution flow to arbitrary code, such as shellcode injected in the payload. Remote exploitation is possible because the web interface is accessible over the network, often without authentication. Public exploits demonstrate sending crafted requests to port 80, leading to full device compromise and root access. The vulnerability is critical due to the ease of remote attack and public exploit availability, enabling network infiltration, malware deployment, or botnet recruitment.
Platform: D-Link DIR-822K
Version: 1.00
Vulnerability: Buffer Overflow
Severity: Critical
Date: 2025-11-23
Prediction: Patch by 2025-12-10
What Undercode Say:
Analytics:
- Check device version: `curl -s http://192.168.0.1/ | grep “FIRMWARE_VERSION”`
– Send malicious request: `curl -X POST http://192.168.0.1/boafrm/formNtp -d “submit-url=$(python3 -c ‘print(\”A\”500)’)”`
– Analyze firmware function: `objdump -d ./httpd | grep -A 30 “455524:”`
– Extract formNtp file: `binwalk -e firmware.bin`
– Test buffer overflow: `python3 exploit.py –target 192.168.0.1`
How Exploit:
Remote attackers send crafted HTTP POST requests to /boafrm/formNtp with long submit-url parameter to overflow buffer and execute arbitrary code, often using public Python scripts.
Protection from this CVE
Update firmware to patched version, disable remote web management, use network segmentation, and monitor for exploit attempts.
Impact:
Remote code execution, full device compromise, network eavesdropping, botnet enrollment, and unauthorized access.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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