CVE-2016-7552 in Threat Discovery Appliance
Summary
by MITRE
On the Trend Micro Threat Discovery Appliance 2.6.1062r1, directory traversal when processing a session_id cookie allows a remote, unauthenticated attacker to delete arbitrary files as root. This can be used to bypass authentication or cause a DoS.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/28/2022
The Trend Micro Threat Discovery Appliance represents a critical security vulnerability classified as CVE-2016-7552, which demonstrates a severe directory traversal flaw in version 2.6.1062r1. This vulnerability specifically targets the appliance's session management mechanism, where the session_id cookie processing fails to properly validate user input, creating an exploitable path traversal condition that allows remote attackers to execute arbitrary file deletion operations with root privileges. The flaw exists within the appliance's web interface handling of session identifiers, where insufficient input sanitization permits attackers to manipulate cookie values to traverse the file system and access restricted directories beyond the intended application scope.
The technical exploitation of this vulnerability occurs through manipulation of the session_id cookie value, which when processed by the appliance's backend systems, allows attackers to construct malicious file paths that bypass normal access controls. This directory traversal vulnerability stems from improper validation of user-supplied session identifiers, enabling attackers to specify absolute file paths that point to system directories outside the intended application boundaries. The vulnerability is particularly dangerous because it operates without requiring authentication, allowing unauthenticated attackers to leverage the flaw and execute destructive operations that could compromise the entire appliance's functionality. According to CWE classification, this represents a CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability, which directly aligns with the exploitation pattern observed in this specific case.
The operational impact of CVE-2016-7552 extends beyond simple file deletion capabilities, as the vulnerability can be leveraged to achieve complete system compromise through multiple attack vectors. An attacker could potentially delete critical system files, configuration data, or binaries that would render the appliance inoperable, resulting in denial of service conditions that could disrupt network security monitoring and threat detection capabilities. Additionally, the ability to delete arbitrary files as root privileges enables attackers to bypass authentication mechanisms entirely, potentially allowing them to establish persistent access or remove forensic evidence. The vulnerability's remote exploitability means that attackers can target the appliance from external networks without requiring physical access or prior authentication credentials, making it particularly attractive for large-scale attacks against organizations relying on Trend Micro appliances for network security. This flaw directly maps to ATT&CK technique T1210: Exploitation of Remote Services, where adversaries leverage vulnerabilities in network services to gain unauthorized access or execute malicious operations.
Mitigation strategies for CVE-2016-7552 should prioritize immediate patching of the affected Trend Micro Threat Discovery Appliance versions, as the vendor has released security updates to address the directory traversal vulnerability in subsequent firmware releases. Organizations should implement network segmentation to limit access to the appliance to authorized administrative networks only, reducing the attack surface for remote exploitation attempts. Additional protective measures include deploying web application firewalls that can detect and block malicious cookie manipulation attempts, implementing strict input validation for all session-related parameters, and monitoring for anomalous file deletion patterns that might indicate exploitation attempts. Security teams should also conduct regular vulnerability assessments of their network security infrastructure to identify similar path traversal vulnerabilities in other network appliances and systems that may be susceptible to the same class of attack. The remediation process should include comprehensive testing of patched firmware to ensure that the directory traversal vulnerability has been properly addressed while maintaining the appliance's intended functionality and security monitoring capabilities.