CVE-2019-7474 in SonicOS
Summary
by MITRE
A vulnerability in SonicWall SonicOS and SonicOSv, allow authenticated read-only admin to leave the firewall in an unstable state by downloading certificate with specific extension. This vulnerability affected SonicOS Gen 5 version 5.9.1.10 and earlier, Gen 6 version 6.2.7.3, 6.5.1.3, 6.5.2.2, 6.5.3.1, 6.2.7.8, 6.4.0.0, 6.5.1.8, 6.0.5.3-86o and SonicOSv 6.5.0.2-8v_RC363 (VMWARE), 6.5.0.2.8v_RC367 (AZURE), SonicOSv 6.5.0.2.8v_RC368 (AWS), SonicOSv 6.5.0.2.8v_RC366 (HYPER_V).
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Analysis
by VulDB Data Team • 05/23/2020
This vulnerability represents a critical stability issue within SonicWall SonicOS and SonicOSv firewall implementations that allows authenticated read-only administrators to potentially compromise system integrity through certificate manipulation. The flaw specifically manifests when certain certificate extensions are downloaded from the firewall interface, creating a condition that can destabilize the underlying operating system. This represents a privilege escalation vector where users with minimal administrative permissions can trigger system instability, fundamentally undermining the security model of the firewall appliance. The vulnerability affects multiple generations of SonicOS including Gen 5 versions up to 5.9.1.10 and Gen 6 versions across various patch levels, indicating a widespread impact across the product line.
The technical mechanism behind this vulnerability involves the certificate download functionality within the SonicOS interface where specific certificate extensions trigger an improper state handling mechanism within the firewall's operating system. When an authenticated read-only administrator attempts to download a certificate containing particular extensions, the system fails to properly validate or handle these extensions, leading to a state where the firewall's operational stability becomes compromised. This type of vulnerability falls under CWE-248, an unspecified weakness in which an exception is thrown but not properly handled, and can be categorized as a denial of service condition that may also provide a foothold for further exploitation. The vulnerability demonstrates poor input validation and error handling practices within the certificate processing pipeline.
The operational impact of this vulnerability extends beyond simple system instability to potentially enable more sophisticated attacks. An attacker with read-only administrative access could repeatedly trigger this condition to cause service disruption, effectively creating a persistent denial of service scenario against the firewall infrastructure. This vulnerability also creates opportunities for information disclosure or further privilege escalation attacks as the compromised system state may provide additional attack surfaces. The fact that this affects both physical SonicWall appliances and virtualized versions across multiple cloud platforms (VMWARE, AZURE, AWS, HYPER_V) amplifies the potential impact across different deployment environments and increases the attack surface for organizations using SonicWall solutions. Organizations may face service interruptions, potential data exposure, and operational disruptions that could affect network security posture.
Mitigation strategies should focus on immediate patching of affected SonicOS versions to address the root cause in certificate handling mechanisms. Organizations should implement strict access controls to limit read-only administrative privileges and establish monitoring for unusual certificate download activities. Network segmentation and additional security controls should be deployed to detect and respond to potential exploitation attempts. The vulnerability highlights the importance of comprehensive input validation and proper error handling in security-critical applications, particularly those involving certificate management and cryptographic operations. Regular security assessments should be conducted to identify similar weaknesses in certificate processing and system state management functions. Additionally, organizations should consider implementing automated patch management processes to ensure timely remediation of similar vulnerabilities across their SonicWall deployments.