OS Command Injection Vulnerability in D-Link DIR-816 Router
CVE-2025-5621

6.9MEDIUM

Key Information:

Vendor: D-link
Status: Dir-816
Vendor: CVE Published:; 5 June 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-5621?

A significant vulnerability has been discovered in the D-Link DIR-816 router, specifically affecting version 1.10CNB05. The issue resides in the qosClassifier function, where improper handling of user inputs for dip_address and sip_address parameters can lead to OS command injection. This vulnerability allows attackers to execute arbitrary commands on the system remotely. It's important to note that this vulnerability impacts devices that are no longer supported, raising serious security concerns for users relying on outdated firmware.

Affected Version(s)

DIR-816 1.10CNB05

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-5621 - Proof of Concept

References

https://vuldb.com/?id.311107

vdb-entrytechnical-description

https://vuldb.com/?ctiid.311107

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https://vuldb.com/?submit.589221

third-party-advisory

CVSS V4

Score:

6.9

Severity:

MEDIUM

Confidentiality:

Low

Integrity:

Low

Availability:

Low

Attack Vector:

Network

Attack Complexity:

Low

Attack Required:

None

Privileges Required:

Undefined

User Interaction: