CVE-2024-3273 Overview
CVE-2024-3273 is a critical command injection vulnerability affecting multiple D-Link Network Attached Storage (NAS) devices. The vulnerability exists in the /cgi-bin/nas_sharing.cgi component of the HTTP GET Request Handler, where improper handling of the system parameter allows unauthenticated remote attackers to execute arbitrary commands on vulnerable devices. This vulnerability affects end-of-life products that will not receive security patches.
Critical Impact
This vulnerability is actively exploited in the wild and has been added to CISA's Known Exploited Vulnerabilities (KEV) Catalog. Remote attackers can achieve complete device compromise without authentication, potentially gaining access to sensitive data stored on NAS devices and using compromised systems as pivot points for further network attacks.
Affected Products
- D-Link DNS-320L (firmware versions 1.01.0702.2013, 1.03.0904.2013, 1.11)
- D-Link DNS-325 (firmware version 1.01)
- D-Link DNS-327L (firmware versions 1.00.0409.2013, 1.09)
- D-Link DNS-340L (firmware version 1.08)
- D-Link DNS-120, DNS-315L, DNS-320, DNS-320LW, DNS-321, DNS-323, DNS-326, DNS-343, DNS-345
- D-Link DNR-202L, DNR-322L, DNR-326
- D-Link DNS-726-4, DNS-1100-4, DNS-1200-05, DNS-1550-04
Discovery Timeline
- April 4, 2024 - CVE-2024-3273 published to NVD
- October 30, 2025 - Last updated in NVD database
Technical Details for CVE-2024-3273
Vulnerability Analysis
This command injection vulnerability targets the nas_sharing.cgi script, a CGI handler responsible for processing network sharing functionality on affected D-Link NAS devices. The vulnerability allows attackers to inject operating system commands through the system parameter in HTTP GET requests. Since the affected devices are network-accessible storage appliances often deployed in small office and home environments, successful exploitation can lead to unauthorized access to all stored data, installation of backdoors or malware, and use of the compromised device for lateral movement within the network.
The vulnerability is particularly dangerous because it requires no authentication—any attacker who can reach the device's web interface can exploit this flaw. D-Link has confirmed these products are end-of-life and will not receive security patches.
Root Cause
The root cause is classified as CWE-77 (Improper Neutralization of Special Elements used in a Command). The nas_sharing.cgi script fails to properly sanitize user-supplied input in the system parameter before passing it to operating system command execution functions. This allows attackers to break out of the intended command context and inject arbitrary shell commands that execute with the privileges of the web server process.
Attack Vector
The attack is network-based and requires no authentication or user interaction. An attacker can craft a malicious HTTP GET request targeting the /cgi-bin/nas_sharing.cgi endpoint with a specially crafted system parameter containing shell metacharacters and arbitrary commands. Upon receiving the request, the vulnerable CGI script processes the malicious input without proper sanitization, resulting in command execution on the underlying operating system.
The exploitation process involves sending crafted HTTP requests to the vulnerable endpoint. Technical details and proof-of-concept information are available through the GitHub PoC Repository and the GreyNoise CVE Analysis.
Detection Methods for CVE-2024-3273
Indicators of Compromise
- HTTP GET requests to /cgi-bin/nas_sharing.cgi containing shell metacharacters (;, |, $(), backticks) in the system parameter
- Unexpected outbound connections from NAS devices to external IP addresses
- Unusual processes running on NAS devices, particularly those spawned by the web server
- Evidence of unauthorized file modifications, new user accounts, or persistence mechanisms on NAS storage
Detection Strategies
- Deploy network intrusion detection rules to identify HTTP requests containing command injection patterns targeting /cgi-bin/nas_sharing.cgi
- Monitor for anomalous network traffic from D-Link NAS devices, including connections to known malicious infrastructure or unexpected external hosts
- Implement web application firewall (WAF) rules to block requests with shell metacharacters in CGI parameters
- Review access logs on D-Link NAS devices for suspicious requests targeting the vulnerable endpoint
Monitoring Recommendations
- Enable comprehensive logging on network perimeter devices to capture traffic to and from D-Link NAS appliances
- Integrate NAS device logs with SIEM solutions for correlation and alerting on exploitation attempts
- Monitor threat intelligence feeds for IP addresses actively scanning for or exploiting CVE-2024-3273
- Conduct regular vulnerability scans to identify any remaining affected devices in the environment
How to Mitigate CVE-2024-3273
Immediate Actions Required
- Isolate all affected D-Link NAS devices from the network immediately, especially from internet-facing segments
- Begin planning for device replacement as these products are end-of-life with no security patches available
- Audit affected devices for signs of compromise, including unauthorized access, modified files, or malicious processes
- Block external access to the management interfaces of any remaining D-Link NAS devices using firewall rules
Patch Information
D-Link has confirmed that all affected products are end-of-life and will not receive security patches. According to the D-Link Security Announcement, the vendor recommends retiring and replacing these devices. This vulnerability is listed in CISA's Known Exploited Vulnerabilities Catalog, requiring federal agencies to take remediation action.
Workarounds
- Disable remote management and internet access to affected NAS devices if immediate replacement is not possible
- Place affected devices on an isolated network segment with strict access controls allowing only essential internal connections
- Implement network-level access controls to restrict which hosts can communicate with the NAS device's web interface
- Consider using a reverse proxy with strict input validation in front of the NAS device as a temporary protective measure
# Example: Block external access to D-Link NAS management interface using iptables
# Identify your NAS device IP address and restrict web interface access
iptables -A INPUT -p tcp --dport 80 -d <NAS_IP> -s ! <TRUSTED_NETWORK> -j DROP
iptables -A INPUT -p tcp --dport 443 -d <NAS_IP> -s ! <TRUSTED_NETWORK> -j DROP
# Block the specific vulnerable CGI endpoint at network level
# Note: This requires a firewall capable of deep packet inspection
# Consult your firewall documentation for URL filtering capabilities
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
