CVE-2019-7483

What is SonicWall SMA100?

The SonicWall SMA100 series is an SSL-VPN appliance providing remote employees with secure access to internal corporate resources — a perimeter device that is a high-value target because compromising it can open a path straight into the internal network.

Overview

CVE-2019-7483 is a directory traversal vulnerability (CWE-22) in the SMA100's handleWAFRedirect CGI script, allowing an unauthenticated remote attacker to test for the presence of specific files on the appliance's filesystem. It is rated high severity (CVSS 7.5) and was patched in late 2019.

Technical Details

The handleWAFRedirect CGI endpoint accepts a file-path-like parameter without adequately validating it against directory-traversal sequences, letting an attacker probe the filesystem outside the web root. While this variant is limited to confirming file existence rather than reading full contents, it can be used for reconnaissance ahead of a more damaging attack, or combined with other flaws for greater impact.

Discovery

Identified and patched by SonicWall as part of routine security maintenance for the SMA100 series in late 2019.

Exploitation Context

CISA added this CVE to the KEV catalog in March 2022, reflecting confirmed exploitation activity against SonicWall SSL-VPN appliances — a product line that has been a recurring target for both opportunistic scanning and targeted ransomware intrusions throughout the early 2020s.

Remediation

1. Update SMA100 firmware to the latest SonicWall-supplied release.
2. Restrict inbound access to the SMA100 management and CGI interfaces to trusted IP ranges only.
3. Monitor web server logs for repeated traversal-style requests (e.g., ../ sequences) against CGI endpoints.
4. Enable available WAF/IPS protections in front of the appliance if supported.
5. Combine with SonicWall's broader hardening guidance for SMA100, including MFA for VPN users.