CVE-2025-70222 Overview
A stack buffer overflow vulnerability has been identified in the D-Link DIR-513 router firmware version 1.10. The vulnerability exists in the curTime parameter handling within the goform/formLogin and goform/getAuthCode endpoints. This memory corruption flaw allows remote attackers to potentially execute arbitrary code or cause a denial of service condition on vulnerable devices without requiring authentication.
Critical Impact
Remote attackers can exploit this stack buffer overflow to execute arbitrary code on vulnerable D-Link DIR-513 routers, potentially leading to complete device compromise, network infiltration, and persistent backdoor access.
Affected Products
- D-Link DIR-513 firmware version 1.10
- D-Link DIR-513 devices with vulnerable goform/formLogin endpoint
- D-Link DIR-513 devices with vulnerable goform/getAuthCode endpoint
Discovery Timeline
- 2026-03-04 - CVE-2025-70222 published to NVD
- 2026-03-05 - Last updated in NVD database
Technical Details for CVE-2025-70222
Vulnerability Analysis
This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow), a critical memory corruption issue that occurs when user-supplied input exceeds the allocated buffer size on the stack. In the context of the D-Link DIR-513 router, the vulnerability manifests when processing the curTime parameter in web form handlers.
The affected endpoints (goform/formLogin and goform/getAuthCode) fail to properly validate the length of the curTime parameter before copying it into a fixed-size stack buffer. This allows an attacker to supply an oversized value that overwrites adjacent memory on the stack, including the return address. By carefully crafting the overflow payload, an attacker can redirect program execution to malicious code.
Since the vulnerability is accessible over the network without authentication, it presents a severe risk to any network where vulnerable D-Link DIR-513 devices are deployed. Successful exploitation could grant attackers full control over the router, enabling them to intercept network traffic, modify DNS settings, or pivot to other devices on the network.
Root Cause
The root cause of this vulnerability is improper input validation in the firmware's web server component. When the curTime parameter is received via HTTP requests to the goform/formLogin or goform/getAuthCode endpoints, the application copies the parameter value into a stack-allocated buffer without verifying that the input length does not exceed the buffer's capacity. This absence of bounds checking allows attackers to trigger a stack buffer overflow condition.
Attack Vector
The attack can be performed remotely over the network by sending a specially crafted HTTP request to the vulnerable D-Link DIR-513 router. The attacker targets either the goform/formLogin or goform/getAuthCode endpoint with an oversized curTime parameter value.
The vulnerability is exploited by sending a malicious HTTP POST request to the vulnerable endpoint containing an oversized curTime parameter. The excessive input data overflows the stack buffer, overwriting the return address and potentially allowing code execution. Technical details and proof-of-concept information are available in the GitHub PoC Repository.
Detection Methods for CVE-2025-70222
Indicators of Compromise
- Unusual HTTP POST requests to goform/formLogin or goform/getAuthCode containing abnormally long curTime parameter values
- Router crashes or unexpected reboots indicating potential exploitation attempts
- Unauthorized configuration changes on D-Link DIR-513 devices
- Suspicious outbound network connections originating from the router
Detection Strategies
- Monitor network traffic for HTTP requests to /goform/formLogin and /goform/getAuthCode with curTime parameters exceeding normal length thresholds
- Implement IDS/IPS rules to detect buffer overflow attack patterns targeting D-Link router endpoints
- Review router logs for repeated authentication failures or malformed request indicators
- Deploy network anomaly detection to identify unusual traffic patterns to and from router management interfaces
Monitoring Recommendations
- Enable logging on network firewalls to capture all traffic directed at router management ports
- Implement SIEM correlation rules to alert on multiple failed router authentication attempts combined with oversized parameter submissions
- Regularly audit D-Link DIR-513 device configurations for unauthorized changes
- Monitor for firmware modification indicators or unexpected router behavior
How to Mitigate CVE-2025-70222
Immediate Actions Required
- Restrict access to the router's web management interface to trusted internal networks only
- Implement firewall rules to block external access to ports 80 and 443 on affected D-Link DIR-513 devices
- Consider disabling remote management features until a patch is available
- Isolate affected devices on a separate network segment where possible
Patch Information
Organizations should consult the D-Link Security Bulletin for official security advisories and firmware updates addressing this vulnerability. Additionally, the D-Link Product Support page provides product-specific firmware downloads and support information.
Workarounds
- Disable remote administration on the D-Link DIR-513 router to limit attack surface
- Place the router behind a separate firewall that restricts access to management interfaces
- Implement network access control lists (ACLs) to permit only authorized IP addresses to access router management endpoints
- Consider replacing end-of-life devices with supported hardware if vendor patches are not forthcoming
# Configuration example - Restrict management interface access via firewall
# Block external access to router management ports
iptables -A INPUT -p tcp --dport 80 -s ! 192.168.1.0/24 -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! 192.168.1.0/24 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
