CVE-2025-32819: SonicWall SMA 100 Auth Bypass Vulnerability

CVE-2025-32819 Overview

CVE-2025-32819 is a path traversal vulnerability affecting SonicWall SMA100 series appliances that allows a remote authenticated attacker with SSLVPN user privileges to bypass path traversal checks and delete arbitrary files on the system. This vulnerability can potentially result in a device reboot to factory default settings, causing significant disruption to network security infrastructure.

Critical Impact

Authenticated attackers can leverage this vulnerability to delete critical system files, potentially forcing the device to reset to factory defaults and disrupting VPN access for the entire organization.

Affected Products

• SonicWall SMA 100 Firmware
• SonicWall SMA 200 / SMA 200 Firmware
• SonicWall SMA 210 / SMA 210 Firmware
• SonicWall SMA 400 / SMA 400 Firmware
• SonicWall SMA 410 / SMA 410 Firmware
• SonicWall SMA 500v / SMA 500v Firmware

Discovery Timeline

• May 7, 2025 - CVE-2025-32819 published to NVD
• May 19, 2025 - Last updated in NVD database

Technical Details for CVE-2025-32819

Vulnerability Analysis

This vulnerability stems from insufficient path traversal validation in the SonicWall SMA100 series firmware. When an authenticated SSLVPN user submits file operation requests, the application fails to properly sanitize path input, allowing attackers to escape the intended directory structure using directory traversal sequences. The vulnerability is classified under CWE-552 (Files or Directories Accessible to External Parties), indicating that the flaw allows unauthorized access to files outside the expected scope.

The attack requires network access and low-privilege authentication (SSLVPN user credentials), making it accessible to any legitimate VPN user who may have been compromised or an insider threat. Once exploited, the attacker gains the ability to delete arbitrary files on the system with the privileges of the web application process.

Root Cause

The root cause of CVE-2025-32819 lies in inadequate input validation within the file handling routines of the SMA100 firmware. The path traversal protection mechanisms can be bypassed, allowing directory traversal sequences such as ../ to navigate outside the intended directory boundaries. This implementation flaw in the path sanitization logic fails to account for certain encoding or traversal techniques that attackers can leverage to reach sensitive system files.

Attack Vector

The attack is executed remotely over the network by an authenticated SSLVPN user. The attacker crafts malicious file path requests containing directory traversal sequences that bypass the security checks. By targeting critical configuration or system files, the attacker can force the device into an unstable state, triggering a factory reset. This attack vector is particularly concerning in enterprise environments where SMA appliances serve as the primary secure remote access gateway.

The exploitation process involves:

1. Authenticating to the SSLVPN portal with valid user credentials
2. Crafting a specially formatted file deletion request with path traversal sequences
3. Bypassing the path validation checks through encoding or other evasion techniques
4. Deleting critical system files to trigger factory reset or denial of service

For detailed technical analysis of this vulnerability, refer to the Rapid7 Blog on SonicWall Vulnerabilities.

Detection Methods for CVE-2025-32819

Indicators of Compromise

• Unexpected device reboots or factory reset events on SMA appliances
• Authentication logs showing unusual file access patterns from SSLVPN users
• System logs containing path traversal sequences such as ../ or encoded variants in file operation requests
• Missing configuration files or unexpected changes to device state

Detection Strategies

• Monitor web application logs for file operation requests containing directory traversal patterns including ../, ..%2f, %2e%2e/, and similar encodings
• Implement network-based detection rules to identify HTTP requests with path traversal sequences targeting SMA appliances
• Configure SIEM alerts for multiple failed file operations followed by successful deletions from the same user session
• Deploy behavioral analysis to detect anomalous file access patterns from SSLVPN user accounts

Monitoring Recommendations

• Enable verbose logging on SMA appliances to capture detailed file operation requests
• Implement real-time log forwarding to a centralized SIEM platform for correlation and analysis
• Configure alerts for unexpected device reboots or configuration changes on SMA appliances
• Regularly audit SSLVPN user accounts and access patterns for suspicious activity

How to Mitigate CVE-2025-32819

Immediate Actions Required

• Apply the latest firmware update from SonicWall that addresses CVE-2025-32819
• Review and audit all SSLVPN user accounts, removing unnecessary access privileges
• Implement network segmentation to limit access to SMA management interfaces
• Enable multi-factor authentication for all SSLVPN users to reduce credential compromise risk
• Monitor SMA appliance logs for signs of exploitation attempts

Patch Information

SonicWall has released a security advisory addressing this vulnerability. Organizations should immediately consult the SonicWall Security Advisory SNWLID-2025-0011 for specific firmware versions that contain the fix. Upgrade all affected SMA100 series appliances to the patched firmware version as soon as possible.

Workarounds

• Restrict SSLVPN access to only essential users until patching is complete
• Implement additional network-level access controls to limit who can reach the SMA appliance
• Deploy a web application firewall (WAF) in front of the SMA appliance to filter path traversal attempts
• Consider temporary isolation of vulnerable appliances if immediate patching is not feasible
• Maintain offline backups of SMA configuration to enable rapid recovery if factory reset occurs

# Example: Export SMA configuration backup before applying patches
# Access via SMA management interface: System > Settings > Export Settings
# Store backup securely offline to enable rapid recovery if needed