CVE-2026-86325 in MGate MB3170
Summary
by MITRE • 10/02/2026
A stack-based buffer overflow vulnerability exists in protocol gateways' account management interface. The vulnerability is caused by insufficient length validation of the `account_name` parameter when processing account management requests. An attacker authenticated as a read-only user to the web management interface could supply a specially crafted account name that exceeds the size of the internal stack buffer, resulting in corruption of program execution flow. Successful exploitation could allow an attacker to read sensitive information from device memory, including credentials, modify arbitrary memory contents, and disrupt device availability.
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Analysis
by VulDB Data Team • 10/02/2026
The vulnerability described is a classic stack-based buffer overflow located within the account management interface of protocol gateways. This flaw stems directly from insufficient length validation applied to the account_name parameter during the processing of account management requests. In secure software design, input data received from external sources or user interfaces must be rigorously validated against expected constraints before being copied into fixed-size memory buffers. The failure to enforce these bounds allows an attacker who has authenticated as a read-only user via the web management interface to supply a specially crafted string that exceeds the allocated size of the internal stack buffer. This misalignment between input length and buffer capacity is the fundamental technical flaw, classified under CWE-120: Buffer Copy without Checking Size of Input.
The operational impact of this vulnerability extends beyond simple denial of service due to its potential for arbitrary code execution or sensitive data exfiltration. When the oversized account name overflows the stack buffer, it corrupts adjacent memory locations on the call stack, including return addresses and saved frame pointers. This corruption allows an attacker to hijack program execution flow, potentially leading to remote code execution with the privileges of the affected service. Even without achieving full control over instruction pointer registers, the overflow can facilitate information disclosure by allowing the reading of sensitive data from device memory, such as stored credentials or session tokens. Furthermore, the ability to modify arbitrary memory contents poses a severe risk to system integrity and availability, potentially causing crashes or unstable behavior that disrupts network operations.
From an attacker perspective, this vulnerability aligns with ATT&CK technique T1059: Command and Scripting Interpreter if exploitation leads to code execution, or more specifically T1078: Valid Accounts when leveraging the initial read-only authentication as a foothold. The requirement for prior authentication limits the attack vector from network-based remote exploitation to local or authenticated remote scenarios depending on how the web interface is exposed. However, even with limited privileges, an attacker can leverage this flaw to escalate their position within the system by extracting credentials that may be reused across other services or devices in the environment.
Mitigation strategies must address both immediate remediation and long-term defensive posture. The primary technical fix involves implementing strict input validation for the account_name parameter, ensuring that its length does not exceed the maximum allowed size defined by the application's buffer constraints. Developers should also employ safe string handling functions that perform bounds checking automatically rather than relying on manual checks which are prone to errors. Additionally, enabling compiler-level protections such as stack canaries (StackGuard), Address Space Layout Randomization (ASLR), and Data Execution Prevention (DEP) can significantly reduce the likelihood of successful exploitation by making it harder for attackers to predict memory layouts or execute injected code. From an operational standpoint, restricting access to the web management interface through network segmentation and enforcing multi-factor authentication adds layers of defense that mitigate the risk posed by compromised read-only accounts. Regular security audits focusing on input validation practices across all user-facing interfaces are essential to prevent similar vulnerabilities in other modules.