CVE-2025-43879 in WRH-733GBK
Summary
by MITRE • 06/24/2025
WRH-733GBK and WRH-733GWH contain an improper neutralization of special elements used in an OS command ('OS Command Injection') vulnerability in the telnet function. If a remote unauthenticated attacker sends a specially crafted request to the affected product, an arbitrary OS command may be executed.
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Analysis
by VulDB Data Team • 06/27/2025
The vulnerability identified as CVE-2025-43879 represents a critical operating system command injection flaw affecting WRH-733GBK and WRH-733GWH network devices. This vulnerability stems from inadequate input validation within the telnet function implementation, creating a pathway for malicious actors to execute arbitrary commands on the underlying operating system. The flaw manifests when the device fails to properly sanitize or neutralize special characters and command sequences that users might inject through telnet connections, allowing attackers to bypass normal access controls and gain unauthorized system access.
The technical exploitation of this vulnerability occurs through the improper neutralization of special elements used in OS commands, which aligns with CWE-77 and CWE-88 classifications under the Common Weakness Enumeration framework. Attackers can craft malicious requests that contain OS command sequences, such as semicolons, pipes, or other shell metacharacters, which are then processed by the device's telnet service without proper sanitization. This creates a direct execution path where attacker-controlled commands are interpreted and executed by the underlying operating system with the privileges of the telnet service account. The vulnerability specifically targets the telnet function, indicating that the device's network management interface lacks adequate input filtering mechanisms to prevent command injection attacks.
From an operational perspective, this vulnerability presents a severe risk to network infrastructure security as it allows remote unauthenticated attackers to execute arbitrary commands on affected devices. The implications extend beyond simple privilege escalation, potentially enabling complete system compromise, data exfiltration, or lateral movement within the network. Attackers could leverage this vulnerability to install backdoors, modify system configurations, access sensitive data, or use the compromised device as a pivot point for attacking other network resources. The lack of authentication requirements for exploitation means that any network-connected attacker with access to the device's telnet service can potentially exploit this vulnerability, making it particularly dangerous in environments where telnet services remain enabled without proper network segmentation or access controls.
The attack surface for this vulnerability is further expanded by the fact that telnet is often enabled by default on many network devices, particularly in legacy systems where administrators may not have disabled the service due to its convenience for remote management. This vulnerability directly maps to techniques described in the MITRE ATT&CK framework under T1059.001 (Command and Scripting Interpreter: PowerShell) and T1021.004 (Remote Services: SSH/Telnet) where adversaries exploit weak input validation in network services to execute malicious commands. Organizations should immediately implement network segmentation to isolate affected devices, disable unnecessary telnet services, and ensure that all devices are updated with patches addressing this command injection vulnerability. The remediation process should include comprehensive network monitoring to detect potential exploitation attempts and implementation of intrusion detection systems that can identify malicious command sequences targeting this specific vulnerability.