CVE-2024-45318: SonicWall SMA 200 Buffer Overflow Flaw

CVE-2024-45318 Overview

CVE-2024-45318 is a stack-based buffer overflow [CWE-121] in the SonicWall SMA100 SSLVPN web management interface. Remote attackers can trigger the overflow without authentication and potentially achieve code execution on affected appliances. The vulnerability impacts the SMA 200, 210, 400, 410, and 500v product lines, which are commonly deployed as remote-access gateways at the network perimeter. SonicWall published advisory SNWLID-2024-0018 to address the issue.

Because SMA100 appliances are internet-facing by design, successful exploitation provides a foothold directly on the edge of the corporate network. The Exploit Prediction Scoring System (EPSS) currently rates the probability of exploitation activity at roughly 1.04%.

Critical Impact

Unauthenticated remote attackers can corrupt stack memory in the SSLVPN management interface and potentially execute arbitrary code on the appliance.

Affected Products

• SonicWall SMA 200 and SMA 210 appliances (firmware)
• SonicWall SMA 400 and SMA 410 appliances (firmware)
• SonicWall SMA 500v virtual appliance (firmware)

Discovery Timeline

• 2024-12-05 - CVE-2024-45318 published to NVD
• 2025-11-04 - Last updated in NVD database

Technical Details for CVE-2024-45318

Vulnerability Analysis

The flaw resides in the web management interface that serves the SSLVPN service on SMA100 series appliances. The interface fails to validate the length of attacker-controlled input before copying it onto a fixed-size stack buffer. This is a textbook stack-based buffer overflow categorized under [CWE-121].

An attacker reaches the vulnerable code path over the network without prior authentication. Once the buffer is overrun, adjacent stack data such as saved return addresses and frame pointers can be overwritten. Depending on the appliance's runtime mitigations, this can be leveraged to redirect control flow and execute attacker-supplied code in the context of the management process.

Root Cause

The root cause is missing or insufficient bounds checking when the SSLVPN web interface processes a request field. The vulnerable function writes more bytes into a stack-allocated buffer than the buffer can hold, corrupting saved registers and control structures on the stack.

Attack Vector

Exploitation is network-based and requires no credentials and no user interaction. An attacker sends a crafted HTTP/HTTPS request to the SSLVPN web management interface. The CVSS vector reports high attack complexity, which is consistent with the need to bypass modern mitigations such as stack canaries and address space layout randomization on the appliance.

No public proof-of-concept exploit, Exploit-DB entry, or CISA Known Exploited Vulnerabilities listing is associated with CVE-2024-45318 at this time. Refer to the SonicWall Vulnerability Advisory SNWLID-2024-0018 for vendor-specific technical context.

Detection Methods for CVE-2024-45318

Indicators of Compromise

• Unexpected restarts, crashes, or core dumps of the SSLVPN web management process on SMA100 appliances.
• Anomalous HTTP/HTTPS requests to the SSLVPN management interface containing oversized headers, parameters, or body fields.
• New or unusual outbound connections initiated from the appliance management interface to unknown infrastructure.

Detection Strategies

• Inspect web server and SSLVPN service logs on the appliance for malformed requests and abnormal termination of worker processes.
• Deploy IDS/IPS signatures that flag overlong fields directed at SMA100 management endpoints.
• Correlate authentication, configuration change, and process crash events from the appliance in a centralized data lake for rapid triage.

Monitoring Recommendations

• Forward SMA100 syslog, audit, and SSLVPN access logs to a SIEM and alert on repeated 5xx responses or service restarts.
• Monitor north-south traffic to the SSLVPN management interface and restrict access to known administrator source ranges.
• Track post-compromise behaviors such as configuration exports, new local accounts, and modified firmware images on the appliance.

How to Mitigate CVE-2024-45318

Immediate Actions Required

• Apply the fixed firmware released by SonicWall as described in advisory SNWLID-2024-0018 for the SMA 200, 210, 400, 410, and 500v models.
• Restrict access to the SSLVPN web management interface to trusted administrative networks until patching is complete.
• Audit appliance configurations, local accounts, and recent firmware changes for signs of tampering.

Patch Information

SonicWall has published fixed firmware versions for the affected SMA100 series appliances. Patch details, version mappings, and upgrade instructions are documented in the SonicWall Vulnerability Advisory SNWLID-2024-0018. Administrators should review the advisory for their specific model and firmware branch before upgrading.

Workarounds

• Limit exposure of the SSLVPN management interface by enforcing source IP allowlists on the upstream firewall.
• Disable the SSLVPN service on appliances that are not actively used for remote access until firmware can be applied.
• Require multi-factor authentication for administrator portals and rotate administrative credentials after patching.

# Configuration example: restrict management access at the upstream firewall
# Replace 203.0.113.0/24 with your administrator network and <SMA_IP> with the appliance address
iptables -A FORWARD -p tcp -s 203.0.113.0/24 -d <SMA_IP> --dport 443 -j ACCEPT
iptables -A FORWARD -p tcp -d <SMA_IP> --dport 443 -j DROP