Inc Ransomware Chains SonicWall Zero-Days for Root Access

Introduction

A sophisticated attack campaign has emerged linking the operators of Inc Ransomware to the exploitation of a dangerous zero-day vulnerability chain targeting SonicWall Secure Mobile Access (SMA) 100 series appliances. By chaining an authentication bypass with a command injection flaw, threat actors are achieving unauthenticated root-level code execution on exposed devices. This development marks a significant escalation in the threat landscape, as it allows ransomware groups to establish a persistent foothold on critical network edge infrastructure without any user interaction or valid credentials. For security teams, the urgency to patch and monitor these appliances has never been higher.

The Anatomy of a Critical Exploit Chain

The attack leverages two distinct vulnerabilities that, when combined, create a devastating pathway to full system compromise. The first vulnerability, tracked as CVE-2024-40766, is an improper access control flaw. It allows an unauthenticated, remote attacker to bypass authentication mechanisms on the SMA appliance's management interface. Essentially, this flaw tricks the system into treating an unauthorized request as if it came from a valid administrative session.

The second vulnerability, CVE-2024-5810, is an OS command injection flaw residing in the appliance's file upload functionality. Under normal circumstances, this vulnerability would require authentication to exploit. However, because CVE-2024-40766 strips away the authentication requirement, attackers can chain them together. The result is a seamless exploit chain: the attacker sends a malicious request that bypasses the login page (CVE-2024-40766) and immediately injects arbitrary operating system commands via the file upload handler (CVE-2024-5810), executing code with root privileges.

Inc Ransomware Operational Profile

Inc Ransomware, also known in the threat intelligence community as IncRansom, has been active since mid-2023. They operate a Ransomware-as-a-Service (RaaS) model and are known for double-extortion tactics—encrypting files while simultaneously exfiltrating sensitive data to leverage on leak sites. Unlike opportunistic groups that spray exploits widely, Inc Ransomware operators typically conduct targeted intrusion, performing reconnaissance to identify high-value targets before deploying their payload.

• Initial Access: Historically reliant on phishing and valid account abuse (VPN/RDP), this pivot to zero-day appliance exploitation signals a maturity upgrade in their capability.
• Post-Exploitation: Once root access is gained on the SMA appliance, actors typically harvest credentials, pivot to internal networks via the SSL-VPN tunnel, and deploy tools like Cobalt Strike or Sliver for command and control.
• Target Sectors: Healthcare, education, government, and manufacturing sectors have been disproportionately targeted, likely due to the prevalence of SonicWall appliances in these verticals.

Impact Assessment and Exposure Risks

The SonicWall SMA 100 series is widely deployed as a remote access gateway, making it a high-value target. A successful compromise of this device effectively hands the attacker the "keys to the kingdom." Because the appliance sits at the network perimeter, root access allows threat actors to:

• Intercept and decrypt VPN traffic passing through the device.
• Modify firewall rules to open backdoors for persistent access.
• Harvest Active Directory credentials cached or processed by the appliance.
• Disable logging and security features to evade detection.
• Use the device as a launchpad for lateral movement into the internal network.

Shodan and Censys data indicate thousands of internet-exposed SMA 100 series interfaces. While SonicWall has released patches, the window between disclosure and mass patching is where the majority of compromises occur. Organizations that have not applied the hotfixes released in late 2024 should assume compromise and initiate incident response procedures immediately.

Immediate Mitigation and Hardening Steps

SonicWall has addressed these vulnerabilities in firmware version 10.2.1.7 and later for the SMA 100 series. However, applying the patch is only the first step. A comprehensive response requires:

1. Immediate Patching: Upgrade all SMA 200, 400, 500, and 1000 series appliances (though 100 series is primary target) to the latest patched firmware immediately.
2. Credential Rotation: Assume all local accounts, VPN user credentials, and AD service accounts configured on the appliance are compromised. Force a global password reset.
3. Certificate Re-issuance: Regenerate and replace SSL/TLS certificates installed on the appliance. The private keys are accessible to a root user.
4. Network Segmentation Review: Ensure the management interface of the SMA appliance is not exposed to the public internet. Restrict access to dedicated management jump hosts or VPNs.
5. Threat Hunting: Deploy YARA rules and Sigma signatures specific to Inc Ransomware post-exploitation artifacts. Check for unexpected SSH keys, crontab entries, or processes running as 'nobody' or 'root' that shouldn't exist.

Conclusion

The exploitation of the SonicWall SMA zero-day chain by Inc Ransomware underscores a harsh reality: network edge devices are the new primary battlefield. Firewalls and VPN gateways are no longer passive infrastructure; they are high-value targets that, when compromised, bypass every internal defense layer. The speed at which ransomware groups operationalize zero-days—moving from proof-of-concept to mass exploitation in days—demands a shift from reactive patching to proactive exposure management. Continuous monitoring of the attack surface, automated firmware compliance checks, and behavioral analytics on network traffic are no longer optional. Grivyonx Cloud provides the AI-driven attack surface management and automated threat detection capabilities necessary to identify these blind spots before adversaries do, ensuring your perimeter holds the line.