Analysis Summary

A critical vulnerability, CVE-2025-32817, has been identified in the SonicWall Connect Tunnel Windows Client, affecting both 32-bit and 64-bit versions up to 12.4.3.283. This flaw allows local attackers with low privileges to create symbolic links that the client mistakenly resolves as valid files. As a result, unauthorized file overwrites can occur, potentially corrupting files and causing a persistent denial-of-service (DoS) condition on the system.

The vulnerability stems from the software’s failure to properly validate and resolve file paths, enabling attackers to craft symbolic links that the service uses without verification. Because this action doesn’t require user interaction and has a low attack complexity, it poses a moderate risk. The vulnerability has been assigned and indicates its local attack nature, potential for file integrity compromise, and high impact on availability.

Exploitation requires local system access, meaning an attacker must already be on the device with the ability to run code at a low privilege level. Upon achieving this, they can misuse the service by injecting malicious symbolic links, leading the VPN client to overwrite legitimate files unknowingly. This could disrupt the system’s functionality, hinder services, or render the client unusable. Importantly, Linux and Mac versions of the Connect Tunnel client are not affected by this vulnerability.

To address this issue, SonicWall has released a patched version 12.4.3.298 and urges all users to update immediately, as no workarounds are currently available. The vulnerability was responsibly disclosed by a Researcher. This incident underscores the ongoing importance of timely software patching and the need for organizations to adopt rigorous vulnerability management practices to defend against emerging threats.

Impact

• Denial of Service
• Gain Access

Indicators of Compromise

CVE

• CVE-2025-32817

Affected Vendors

• SonicWall

Affected Products

• SonicWall Connect Tunnel Windows Client (32/64-bit) versions less than 12.4.3.283

Remediation

• Upgrade to the patched version 12.4.3.298 of the SonicWall Connect Tunnel Windows Client.
• Avoid using any versions up to and including 12.4.3.283, as they are vulnerable.
• Limit local access to systems to trusted users only, reducing the risk of low-privileged user exploitation.
• Regularly perform security reviews and file integrity checks on systems running SonicWall software.
• Use endpoint protection and monitoring tools to detect and alert on suspicious symbolic link activity.
• Ensure timely patching and updates as part of a formal vulnerability management program.
• Inform IT staff and affected users about the vulnerability and the importance of applying the update.
• Confirm that version 12.4.3.298 has been successfully deployed across all affected systems.