CVE-2026-124010 in XWEB EVO
Summary
by MITRE • 11/12/2026
XWEB EVO before 5.6.2 contains a command injection vulnerability that allows unauthenticated remote attackers to execute arbitrary commands as root by exploiting the setuid-root CGI xwconsole.cgi. Attackers can supply malicious input through the sh parameter, which is passed unsanitized to popen(), to achieve full system compromise. This product line reached it's end of service date in March 2026.
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Analysis
by VulDB Data Team • 11/12/2026
The vulnerability identified in XWEB EVO versions prior to 5.6.2 represents a critical security flaw rooted in improper input validation and the misuse of privileged execution contexts within its web management interface. Specifically, the CGI script named xwconsole.cgi operates with setuid-root privileges, meaning it executes with the highest level of system authority regardless of the user account initiating the request. This architectural decision creates a high-value target for attackers because any successful exploitation path leads directly to root-level access on the underlying operating system. The core technical flaw lies in how this script handles input parameters passed via HTTP requests. When an unauthenticated remote attacker interacts with the interface, they can inject malicious payloads into specific fields that are subsequently processed by shell commands without adequate sanitization or escaping mechanisms.
The mechanism of exploitation centers on the sh parameter within the xwconsole.cgi script. This parameter is directly concatenated and passed to the popen() function, which opens a pipe to execute a command in a subshell environment provided by /bin/sh. Because the input from this parameter is not validated against expected character sets or restricted commands, an attacker can inject shell metacharacters such as semicolons, pipes, or backticks to break out of the intended context and append arbitrary system commands. For instance, by appending a command like ; rm -rf / after legitimate input, the underlying shell interprets this as two separate instructions rather than part of a single string parameter. This lack of separation between data and code allows for full remote code execution with root privileges, effectively bypassing all authentication controls since no valid credentials are required to trigger the vulnerability.
From an operational impact perspective, this vulnerability is severe due to its combination of unauthenticated access and privilege escalation capabilities. An attacker does not need prior knowledge of system passwords or network segmentation details beyond basic connectivity to exploit it. Once executed, the compromise allows for complete control over the device, including reading sensitive configuration files, modifying system settings, installing persistent backdoors, pivoting into internal networks if the device serves as a gateway, and exfiltrating data stored on the appliance. The presence of setuid-root binaries in web-facing applications is generally considered an anti-pattern in secure software development because it amplifies the blast radius of any input validation failure. In this case, the flaw transforms a simple web form submission into a full system takeover vector, undermining the integrity and availability of the entire network infrastructure protected by or connected to the XWEB EVO device.
This vulnerability aligns with CWE-78 Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The specific technique of using popen() without sanitizing input is a classic example of this weakness. Furthermore, from a tactical perspective within the MITRE ATT&CK framework, this exploitation falls under T1059 Command and Scripting Interpreter, specifically leveraging shell commands to execute arbitrary code. It also relates to T1136 False Positives if attackers attempt to mask their activities using legitimate-looking parameters before injecting malicious payloads. The reliance on setuid-root for administrative functions in a CGI script exacerbates the risk by ensuring that any successful injection results in maximum privilege levels, which is inconsistent with the principle of least privilege recommended by industry security standards such as CIS Benchmarks and NIST guidelines for secure system configuration.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary recommendation is to upgrade XWEB EVO to version 5.6.2 or later, where this input validation flaw has been corrected through proper sanitization of the sh parameter before it reaches the shell interpreter. If upgrading is not immediately feasible due to operational constraints, network-level controls should be implemented to restrict access to the management interface exclusively from trusted IP addresses using firewalls or VLAN segmentation. Additionally, disabling unnecessary CGI scripts that require elevated privileges can reduce the attack surface. Long-term mitigation involves refactoring the application logic to avoid running web-facing components with root permissions entirely. Administrative functions should be separated into distinct processes that authenticate users before escalating privileges only for specific, validated actions, rather than relying on setuid binaries for general command execution. Given that this product line reached its end of service date in March 2026, organizations are strongly advised to plan for hardware replacement or migration to supported platforms to ensure continued security updates and compliance with modern cybersecurity standards.