CVE-2018-9059 in Web Server
Summary
by MITRE
Stack-based buffer overflow in Easy File Sharing (EFS) Web Server 7.2 allows remote attackers to execute arbitrary code via a malicious login request to forum.ghp. NOTE: this may overlap CVE-2014-3791.
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Analysis
by VulDB Data Team • 10/24/2025
The vulnerability identified as CVE-2018-9059 represents a critical stack-based buffer overflow flaw within the Easy File Sharing Web Server version 7.2 that enables remote code execution through manipulated authentication requests. This issue specifically targets the forum.ghp endpoint, which serves as a login interface for the web server's file sharing functionality. The vulnerability stems from inadequate input validation mechanisms that fail to properly handle excessively long or malformed data payloads during the authentication process, creating a exploitable condition where attacker-controlled data can overwrite adjacent memory locations on the stack.
The technical implementation of this vulnerability involves a classic stack buffer overflow scenario where a fixed-size buffer allocated on the stack receives more data than it can accommodate. When remote attackers craft malicious login requests containing oversized payloads, particularly within the username or password fields, the web server's authentication handler fails to enforce proper bounds checking. This allows the overflow to overwrite return addresses, saved registers, and other critical stack frame data, potentially enabling attackers to redirect program execution flow to malicious code injected into the buffer. The vulnerability's classification under CWE-121 stack-based buffer overflow aligns with established patterns where insufficient input validation leads to memory corruption that can be leveraged for privilege escalation and arbitrary code execution.
From an operational perspective, this vulnerability presents a severe risk to organizations relying on Easy File Sharing Web Server 7.2 for file sharing and collaboration services. The remote execution capability means attackers can exploit this vulnerability without requiring physical access or local network presence, making it particularly dangerous for publicly accessible web servers. The impact extends beyond simple code execution to include potential privilege escalation, data exfiltration, and persistent backdoor establishment. Attackers could leverage this vulnerability to gain full control over the affected server, potentially using it as a pivot point for further network reconnaissance and lateral movement attacks. The overlap with CVE-2014-3791 suggests this represents a recurring flaw in the software's authentication handling that has persisted across multiple versions, indicating inadequate code review and security testing practices during development cycles.
Mitigation strategies for CVE-2018-9059 should prioritize immediate patch deployment from the vendor, as this vulnerability has been widely documented and exploited in the wild. Organizations lacking immediate patch availability should implement network-level restrictions such as firewall rules that limit access to the affected forum.ghp endpoint and restrict external exposure of the web server. Additionally, implementing input validation controls at the application level, including length restrictions and proper sanitization of authentication parameters, can provide defense-in-depth measures. Security monitoring should focus on detecting anomalous login patterns and unusually large request payloads that might indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1210 exploitation for privilege escalation and T1071 application layer protocol usage, making it particularly relevant for threat hunting and incident response activities. Organizations should also consider implementing intrusion detection systems that can identify the specific payload patterns associated with this vulnerability to enhance their detection capabilities.