CVE-2023-41715: SonicWall SonicOS Privilege Escalation

CVE-2023-41715 Overview

CVE-2023-41715 is an Improper Privilege Management vulnerability (CWE-269) affecting the SonicOS SSL VPN Tunnel component. This post-authentication flaw allows authenticated users to escalate their privileges within the VPN tunnel, potentially gaining unauthorized access to resources and capabilities beyond their intended authorization level.

The vulnerability exists in SonicWall's SonicOS operating system across a wide range of firewall appliances, including the NSA, TZ, NSV, NSSP, SM, and SOHO series. An attacker who has already authenticated to the SSL VPN can exploit this vulnerability to elevate their privileges, potentially compromising the security posture of the entire network segment protected by the affected appliance.

Critical Impact

Authenticated VPN users can escalate privileges within the SSL VPN tunnel, potentially gaining administrative-level access and compromising network security controls.

Affected Products

• SonicWall SonicOS (multiple firmware versions)
• SonicWall NSA Series (NSA2700, NSA3700, NSA4700, NSA5700, NSA6700, NSA 2600/2650/3600/3650/4600/4650/5600/5650/6600/6650)
• SonicWall TZ Series (TZ270/270W, TZ370/370W, TZ470/470W, TZ570/570P/570W, TZ670, TZ 300/300P/300W/350/400/400W/500/500W/600/600P)
• SonicWall NSSP Series (NSSP10700, NSSP11700, NSSP13700, NSSP15700)
• SonicWall NSV Virtual Firewalls (NSV10, NSV25, NSV50, NSV100, NSV200, NSV270, NSV300, NSV400, NSV470, NSV800, NSV870, NSV1600)
• SonicWall SM Series (SM 9200/9250/9400/9450/9600/9650)
• SonicWall SOHO Series (SOHO 250, SOHO 250W, SOHOW)

Discovery Timeline

• October 17, 2023 - CVE-2023-41715 published to NVD
• May 2, 2025 - Last updated in NVD database

Technical Details for CVE-2023-41715

Vulnerability Analysis

This vulnerability represents an Improper Privilege Management flaw within the SonicOS SSL VPN Tunnel functionality. The weakness allows authenticated VPN users to bypass authorization controls and elevate their privileges beyond what their assigned user role permits. This type of vulnerability is particularly dangerous in enterprise environments where different user groups are granted varying levels of VPN access based on their organizational role and need-to-know requirements.

The attack requires valid credentials to establish an SSL VPN session, making this a post-authentication exploit. However, once authenticated, even a low-privileged user could potentially gain elevated access to sensitive network resources, bypass access control lists (ACLs), or perform administrative actions they are not authorized to execute.

Root Cause

The root cause stems from improper privilege management (CWE-269) in the SSL VPN tunnel handling code within SonicOS. The operating system fails to properly enforce privilege boundaries for authenticated VPN sessions, allowing privilege context to be manipulated or escalated within the established tunnel. This indicates insufficient validation of user privilege levels during VPN session operations or improper separation between different privilege domains within the tunnel architecture.

Attack Vector

The attack is network-based and requires low-privilege authentication as a prerequisite. An attacker must first obtain valid VPN credentials through legitimate means, credential theft, or social engineering. Once authenticated to the SSL VPN service, the attacker can exploit the privilege management flaw to escalate their access rights within the VPN tunnel context.

The exploitation process involves:

1. Establishing a legitimate SSL VPN connection using valid credentials
2. Exploiting the improper privilege management flaw within the tunnel session
3. Gaining elevated privileges that allow access to restricted resources or administrative functions
4. Potentially pivoting to compromise additional network assets accessible through the elevated privilege level

No public exploit code is currently available for this vulnerability. Organizations should consult the SonicWall Vulnerability Advisory SNWLID-2023-0012 for detailed technical information and remediation guidance.

Detection Methods for CVE-2023-41715

Indicators of Compromise

• Unusual VPN session activity patterns showing access to resources outside normal user scope
• SSL VPN log entries indicating privilege changes or authorization bypass attempts
• Unexpected administrative actions performed from VPN user sessions
• Authentication logs showing legitimate user credentials followed by elevated privilege operations

Detection Strategies

• Implement SSL VPN session monitoring to detect privilege escalation attempts within active tunnels
• Enable verbose logging on SonicWall appliances for SSL VPN authentication and authorization events
• Deploy network traffic analysis to identify anomalous access patterns from VPN endpoints
• Configure SIEM rules to correlate VPN authentication events with subsequent high-privilege operations

Monitoring Recommendations

• Monitor SonicOS system logs for unusual privilege elevation events in the SSL VPN module
• Establish baseline VPN user behavior profiles to identify deviation from normal access patterns
• Review VPN access logs regularly for signs of lateral movement or unauthorized resource access
• Implement real-time alerting for administrative actions performed through VPN sessions by non-admin users

How to Mitigate CVE-2023-41715

Immediate Actions Required

• Update all affected SonicWall appliances to the latest patched firmware version
• Review and restrict SSL VPN user permissions to enforce the principle of least privilege
• Audit current VPN user accounts and remove unnecessary access rights
• Enable multi-factor authentication for all SSL VPN access to add an additional security layer
• Implement network segmentation to limit potential impact of privilege escalation

Patch Information

SonicWall has released security updates to address this vulnerability. Administrators should immediately apply the patches referenced in the SonicWall Vulnerability Advisory SNWLID-2023-0012. The advisory provides specific firmware versions that address CVE-2023-41715 for each affected hardware platform.

Given the large number of affected products across multiple hardware generations, organizations should inventory all SonicWall appliances and verify firmware versions against the patched versions listed in the advisory.

Workarounds

• If immediate patching is not possible, consider temporarily disabling SSL VPN functionality until patches can be applied
• Implement strict IP-based access controls for SSL VPN services to limit exposure
• Deploy additional network monitoring at the VPN gateway to detect suspicious privilege escalation behavior
• Consider implementing a defense-in-depth approach with additional authentication requirements for sensitive resources accessed via VPN

# Verify SonicOS firmware version via CLI
show version

# Review SSL VPN user group configurations
show user local group

# Check current SSL VPN access policies
show vpn ssl server access

# Review authentication settings
show user auth-method