Security researchers

Security Advisory

RCE Risk in D-Link Routers due to Hardcoded Telnet Credentials

Summary A significant security flaw (CVE-2025-46176) has exposed thousands of D-Link routers to remote code execution attacks through hardcoded Telnet credentials embedded in firmware. This is affecting its DIR-605L and DIR-816L routers.

If successful exploitation happens this will enables attackers to modify router configurations, deploy malware, or pivot into internal networks.

OEMD-link
SeverityMedium
CVSS Score6.5
CVEsCVE-2025-46176
Actively ExploitedNo
Exploited in WildNo
Advisory Version1.0

Overview

The flaw exposes devices to remote command execution (RCE) through hardcoded Telnet credentials.

The vulnerability has been rated medium in severity (CVSS 6.5), with no official firmware patch available as of May 2025.

Vulnerability NameCVE IDProduct AffectedSeverityFixed Version
​Hardcoded Telnet Credentials vulnerability  CVE-2025-46176D-Link Router  MediumNo official fix available

Technical Summary

The vulnerability arises from hardcoded Telnet credentials in the router firmware, which allows unauthenticated remote attackers to execute arbitrary commands.

Firmware analysis revealed embedded credentials in configuration files used during Telnet service initialization.

Security experts recommended retiring these EOL devices due to absence of security support and the impossibility of removing hardcoded credentials through configuration changes.

CVE IDSystem AffectedVulnerability DetailsImpact
    CVE-2025-46176D-Link DIR-605L v2.13B01, DIR-816L v2.06B01Telnet service (/usr/sbin/telnetd -l /bin/sh -u Alphanetworks:$image_sign) uses hardcoded credentials from image_sign file, exposing plaintext passwords.      RCE

Recommendations:

As of May 2025, no firmware updates are available to fix the vulnerability. Recommended temporary mitigations include :

  • Disable Telnet access via the router’s web interface.
  • Block Telnet port (23) using firewall rules:

“iptables -A INPUT -p tcp –dport 23 -j DROP”

  • Restrict WAN access to management interfaces.
  • Monitor D-Link’s official support page for firmware updates.

Conclusion:
Security researchers discovered the flaw through firmware analysis, revealing that both router models contain default Telnet credentials that cannot be changed by users. 

While exploitation likelihood is currently assessed as low, vulnerability enables unauthenticated attackers to gain control of the routers, affecting confidentiality, integrity and availability.

Immediate mitigation is advised, especially for publicly exposed devices and Security experts strongly recommend retiring these EOL devices due to the absence of security support and the impossibility of removing hardcoded credentials through configuration changes.

Threat from Legacy Devices:

The vulnerability in Telnet revealed security risks that legacy networking equipment carry with them and is embedded hardcoded credentials in IoT devices.

Inadequate security, harboring multiple unpatched vulnerabilities and relying on inadequate security controls that fail to address underlying risks. This poses a threat not only to device itself, but also to the network and connected critical assets.

References:

Security Advisory

Windows 11 DLL Flaws Open Doors to Privilege Escalation! 

Summary 

Security researcher John Ostrowski of Compass Security has uncovered two privilege escalation vulnerabilities in Microsoft Windows CVE-2025-24076 and CVE-2025-24994.

DLL hijacking is a technique that exploits how Windows applications load DLLs.

OEM Windows 
Severity HIGH 
CVSS Score 7.3 
CVEs CVE-2025-24994, CVE-2025-24076 
No. of Vulnerabilities Patched 02 
Actively Exploited Yes 
Exploited in Wild Yes 
Advisory Version 1.0 

Overview 

These flaws, found in the Mobile Devices management component, stem from insecure DLL loading behavior that could allow unprivileged users to escalate privileges to SYSTEM via a DLL hijacking attack. Microsoft has released fixes for both vulnerabilities as part of its March 2025 Patch Tuesday rollout. 

Vulnerability Name CVE ID Product Affected Severity CVSS Score 
​Windows Cross Device Service Elevation of Privilege Vulnerability  CVE-2025-24076 Windows  HIGH  7.3 
​Windows Cross Device Service Elevation of Privilege Vulnerability CVE-2025-24994 Windows HIGH 7.3 

Technical Summary 

The vulnerability arises due to Windows 11’s “Mobile devices” functionality loading a DLL from a user-writable location without verifying its signature. This enables unprivileged users to replace the DLL with a malicious proxy that executes with elevated privileges. 

CVE ID System Affected Vulnerability Details Impact 
  CVE-2025-24076  Windows 11 Version 22H2, 22H3, 23H2, 24H2.  Exploits a race condition in the “Mobile devices” feature via DLL hijacking. The system process loads CrossDevice.Streaming.Source.dll from a user-writable directory (%PROGRAMDATA%\CrossDevice\), allowing privilege escalation when replaced with a malicious DLL. Attackers used Opportunistic Locks and API hooking (via Detours) to reliably exploit the narrow timing window.   Allows SYSTEM-level privilege escalation 
CVE-2025-24994 Windows 11 Version 22H2, 22H3, 23H2, 24H2 Involves a similar DLL hijacking flaw in a user-to-user context. A user-level process loads a DLL without signature validation, allowing a malicious DLL to be executed under another user’s context. This vector is less severe but still exploitable.  Allows user-to-user privilege escalation 

Remediation: 

  • Implement Security Updates to make sure to install the current security patches made available by Microsoft, specifically March 2025 updates, into affected systems. 
  • Turn off Cross Device Service if not needed, disable the “Mobile Devices” feature in Windows 11 to avoid exploitation of the vulnerabilities. 
  • Look for Suspicious Activity constantly scan system logs for suspect activity, particularly attempts to alter or load DLL files in protected processes. 
  • Restrict User Permissions prevent non-administrative users from changing system files or running processes with elevated privileges. 
  • Support DLL Signature Verification makes all programs support DLL signature verification so that no applications can load unsigned or altered DLL files. 

Conclusion: 
The discovered DLL hijacking vulnerabilities in Windows 11’s “Mobile devices” feature demonstrate how legacy attack techniques remain potent when integrated into new OS functionalities.

The presence of a working Proof-of-Concept (PoC) reinforces the practical risk posed by these flaws. Organizations should immediately apply the March 2025 security updates and consider employing EDR solutions to monitor for related behavior. Continued vigilance and file access control hardening remain essential in defending against such privilege escalation attacks.  

While CVE-2025-24076 enables SYSTEM-level access but CVE-2025-24994 arises from a related user-level process failing to validate DLLs.

This opens the door to user-to-user attacks, though its impact is far less severe compared to its SYSTEM-targeting sibling.

References: 


 

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