CVE-2018-25237 in Hirschmann HiSecOS Classic Firewall
Summary
by MITRE • 04/04/2026
Hirschmann HiSecOS devices versions prior to 05.3.03 contain a buffer overflow vulnerability in the HTTPS login interface when RADIUS authentication is enabled that allows remote attackers to crash the device or execute arbitrary code by submitting a password longer than 128 characters. Attackers can exploit improper bounds checking in password handling to overflow a fixed-size buffer and achieve denial of service or remote code execution.
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Analysis
by VulDB Data Team • 04/04/2026
The vulnerability identified as CVE-2018-25237 affects Hirschmann HiSecOS network security devices running firmware versions prior to 05.3.03. This issue resides within the HTTPS login interface specifically when RADIUS authentication is configured, making it particularly concerning for organizations relying on centralized authentication mechanisms. The flaw represents a critical security weakness that undermines the integrity and availability of network infrastructure devices.
The technical root cause of this vulnerability stems from improper bounds checking within the password handling mechanism of the HTTPS login interface. When a user submits a password exceeding 128 characters in length, the system fails to properly validate the input size against a predetermined buffer capacity. This buffer overflow condition occurs because the device allocates a fixed-size buffer that cannot accommodate passwords exceeding the specified threshold, leading to memory corruption when the excessive input is processed. The vulnerability manifests as a classic stack-based buffer overflow, where the overflowed data overwrites adjacent memory locations including return addresses and control data.
From an operational perspective, this vulnerability presents severe implications for network security infrastructure. Remote attackers can exploit this weakness to either crash the affected device, resulting in denial of service that disrupts network connectivity and security services, or potentially execute arbitrary code with elevated privileges. The ability to achieve remote code execution means that attackers could gain full control over the device, potentially using it as a foothold for further network infiltration or to compromise other connected systems. The vulnerability's remote exploitability eliminates the need for physical access or network proximity, making it particularly dangerous in enterprise environments.
The impact of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a significant concern from an ATT&CK framework perspective under the T1210 technique for exploitation of remote services. Organizations using affected HiSecOS devices face potential exposure to credential theft, unauthorized access to network resources, and complete device compromise. The vulnerability's presence in the authentication interface specifically targets the most critical security control point of network devices, potentially undermining all other security measures implemented within the network infrastructure.
Mitigation strategies should prioritize immediate firmware updates to version 05.3.03 or later, which contain the necessary patches to address the buffer overflow condition. Network administrators should also implement network segmentation to limit access to affected devices, disable unnecessary authentication methods, and monitor for suspicious login attempts or device behavior. Additionally, organizations should conduct comprehensive vulnerability assessments to identify any other potentially affected devices within their network infrastructure and establish robust monitoring procedures to detect exploitation attempts. The remediation process should include thorough testing of updated firmware in controlled environments before deployment to production systems to ensure continued device functionality and avoid unintended service disruptions.