CVE-2016-2397 in SonicWall
Summary
by MITRE
The cliserver implementation in Dell SonicWALL GMS, Analyzer, and UMA EM5000 7.2, 8.0, and 8.1 before Hotfix 168056 allows remote attackers to deserialize and execute arbitrary Java code via crafted XML data.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability identified as CVE-2016-2397 represents a critical deserialization flaw within the cliserver component of Dell SonicWALL Global Management System GMS, Analyzer, and UMA EM5000 appliances. This issue affects versions 7.2, 8.0, and 8.1 prior to Hotfix 168056, creating a significant attack surface that enables remote code execution through maliciously crafted XML data. The vulnerability stems from the improper handling of serialized Java objects within the application's communication protocols, specifically exposing the deserialization mechanism to untrusted input sources.
The technical exploitation of this vulnerability occurs when remote attackers send specially crafted XML payloads to the affected SonicWALL appliances. These payloads contain serialized Java objects that, upon deserialization, trigger arbitrary code execution within the target system's Java runtime environment. The flaw exists because the application fails to validate or sanitize input data before processing serialized objects, allowing attackers to inject malicious payloads that bypass normal security controls. This type of vulnerability is classified as a deserialization vulnerability under CWE-502, specifically involving unsafe deserialization patterns that enable remote code execution through object instantiation.
The operational impact of this vulnerability extends beyond simple remote code execution, as it provides attackers with complete control over the affected appliances. Successful exploitation allows adversaries to execute arbitrary commands with the privileges of the running service, potentially leading to full system compromise, data exfiltration, or use as a foothold for further network infiltration. The vulnerability affects critical network security infrastructure, making it particularly dangerous as it could enable attackers to bypass network security controls, modify firewall rules, or disrupt network operations. This represents a significant concern for organizations relying on SonicWALL appliances for their network security posture.
Organizations should implement immediate mitigations including applying the vendor-provided hotfix 168056, which addresses the deserialization vulnerability in the cliserver component. Network segmentation and firewall rules should be implemented to restrict access to affected appliances from untrusted networks, while monitoring should be enhanced to detect suspicious XML traffic patterns. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, and T1566.001 for spearphishing attachments, as attackers may leverage this vulnerability to establish persistent access. Additionally, implementing application whitelisting policies and disabling unnecessary network services can reduce the attack surface, while regular security assessments should be conducted to identify similar vulnerabilities in other enterprise applications. The remediation process should include thorough testing of the hotfix in non-production environments before deployment to ensure operational stability and prevent service disruption.