CVE-2025-45058: D-Link DI-8300 Buffer Overflow Vulnerability

CVE-2025-45058 Overview

A buffer overflow vulnerability has been discovered in D-Link DI-8300 router firmware version 16.07.26A1. The vulnerability exists in the jingx_asp function, which improperly handles the fx parameter, allowing attackers to trigger a buffer overflow condition. This flaw enables remote attackers to cause a Denial of Service (DoS) by sending specially crafted input to the affected device.

Critical Impact

Remote attackers can crash vulnerable D-Link DI-8300 routers without authentication, disrupting network connectivity for all connected devices.

Affected Products

• D-Link DI-8300 firmware version 16.07.26A1
• D-Link DI-8300 routers running vulnerable firmware versions

Discovery Timeline

• 2026-04-08 - CVE-2025-45058 published to NVD
• 2026-04-09 - Last updated in NVD database

Technical Details for CVE-2025-45058

Vulnerability Analysis

This vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), commonly known as a classic buffer overflow. The jingx_asp function in the D-Link DI-8300 firmware fails to properly validate the length of data supplied through the fx parameter before copying it into a fixed-size buffer. When an attacker provides input that exceeds the expected buffer size, the overflow corrupts adjacent memory regions, leading to application crashes and denial of service conditions.

The attack can be executed remotely over the network without requiring any authentication or user interaction. This makes the vulnerability particularly dangerous for exposed devices, as attackers can repeatedly crash the router, effectively denying network services to legitimate users.

Root Cause

The root cause of this vulnerability is insufficient input validation in the jingx_asp function. The function accepts user-controlled data through the fx parameter but does not verify that the input length falls within acceptable bounds before performing memory operations. This is a classic example of unsafe memory handling in embedded firmware, where resource constraints sometimes lead developers to omit proper boundary checks.

Attack Vector

The vulnerability is exploited via network-based requests targeting the jingx_asp function on the D-Link DI-8300 router. An attacker crafts a malicious request containing an oversized fx parameter value. When the router processes this request, the jingx_asp function attempts to copy the malicious input into a fixed-size buffer, causing memory corruption.

The exploitation requires no authentication, and the attacker simply needs network access to the device's management interface. The attack results in a crash of the affected service or the entire device, requiring a manual restart to restore functionality. Repeated exploitation can result in a sustained denial of service condition.

Technical details and proof-of-concept information can be found in the GitHub IoT Vulnerability Collection.

Detection Methods for CVE-2025-45058

Indicators of Compromise

• Unexpected router reboots or service interruptions without apparent cause
• Unusual network traffic patterns targeting the router's web management interface
• Large or malformed HTTP requests containing oversized parameter values directed at the router
• Log entries showing crashes or errors related to the jingx_asp function

Detection Strategies

• Deploy network intrusion detection systems (IDS) to monitor for malformed HTTP requests targeting D-Link router management interfaces
• Implement anomaly detection for traffic patterns that include unusually large parameter values in web requests
• Monitor router health metrics for unexpected restarts or availability issues
• Configure alerting for repeated connection attempts to the router's management interface from external sources

Monitoring Recommendations

• Enable logging on the D-Link DI-8300 router to capture access attempts and errors
• Implement network monitoring to track traffic destined for the router's management ports
• Set up availability monitoring to detect service disruptions indicative of DoS attacks
• Review network traffic logs for requests containing abnormally large payloads

How to Mitigate CVE-2025-45058

Immediate Actions Required

• Restrict access to the router's management interface to trusted internal networks only
• Disable remote management features if not required
• Implement network segmentation to isolate the affected router from untrusted networks
• Consider replacing end-of-life D-Link devices with actively supported alternatives

Patch Information

Check the D-Link Security Bulletin for official firmware updates addressing this vulnerability. Users should also visit the D-Link Product Information page for the latest firmware releases and support information.

Note: If the D-Link DI-8300 has reached end-of-life status and no patches are available, device replacement is strongly recommended.

Workarounds

• Configure firewall rules to block external access to the router's management interface
• Use access control lists (ACLs) to limit management access to specific IP addresses
• Deploy the router behind a network firewall that can filter malicious requests
• Disable unnecessary web-based management services if alternative management methods are available

# Example firewall rule to restrict management interface access
# Allow management access only from trusted internal network
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP