CVE-2017-8051 in Appliance
Summary
by MITRE
Tenable Appliance 3.5 - 4.4.0, and possibly prior versions, contains a flaw in the simpleupload.py script in the Web UI. Through the manipulation of the tns_appliance_session_user parameter, a remote attacker can inject arbitrary commands.
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Analysis
by VulDB Data Team • 01/02/2025
The vulnerability identified as CVE-2017-8051 affects Tenable Appliance versions 3.5 through 4.4.0, representing a critical command injection flaw within the web user interface. This issue stems from insufficient input validation in the simpleupload.py script, which processes file upload operations through the web interface. The vulnerability specifically manifests when an attacker manipulates the tns_appliance_session_user parameter, allowing for arbitrary code execution on the affected system. The flaw represents a severe security weakness that could enable unauthorized users to gain full control over the appliance's operations and potentially compromise the entire network infrastructure relying on the appliance for security monitoring.
The technical nature of this vulnerability aligns with CWE-77, which describes improper neutralization of special elements used in command execution contexts. The vulnerability exists because the web application fails to properly sanitize user-supplied input before incorporating it into system commands. When the tns_appliance_session_user parameter is manipulated, the application directly uses this value in command execution contexts without adequate validation or sanitization. This creates an environment where attacker-controlled input can be interpreted as executable commands, enabling remote code execution. The flaw operates at the application layer and requires no authentication for exploitation, making it particularly dangerous as it can be leveraged by remote attackers without prior access credentials.
The operational impact of this vulnerability extends beyond simple command injection, as it provides attackers with complete control over the Tenable appliance's functionality. An attacker could execute arbitrary system commands, potentially leading to data exfiltration, system compromise, or disruption of security monitoring services. The appliance serves as a critical security tool for network monitoring and vulnerability assessment, so compromising it would undermine the organization's ability to detect and respond to security incidents. Additionally, the vulnerability affects multiple versions of the appliance, indicating a widespread issue that would require extensive patching efforts across affected organizations. The flaw's remote exploitability means that attackers can target the appliance from outside the network perimeter, potentially enabling lateral movement within compromised networks.
Organizations should immediately implement mitigations including applying the vendor-provided security patches and updates to address the command injection vulnerability. Network segmentation and access controls should be strengthened to limit exposure of the appliance to untrusted networks. Regular security assessments and monitoring of the appliance's web interface should be conducted to detect potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and output encoding in web applications, aligning with ATT&CK technique T1059 for command and scripting interpreter. Organizations should also consider implementing web application firewalls to detect and block malicious parameter manipulation attempts, while maintaining comprehensive logging of all web interface activities for forensic analysis purposes. The incident highlights the critical need for regular security testing and vulnerability management processes to identify and remediate similar flaws before they can be exploited by threat actors.