CVE-2018-19862 in MiniShare
Summary
by MITRE
Buffer overflow in MiniShare 1.4.1 and earlier allows remote attackers to execute arbitrary code via a long HTTP POST request. NOTE: this product is discontinued.
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Analysis
by VulDB Data Team • 10/25/2025
The vulnerability identified as CVE-2018-19862 represents a critical buffer overflow flaw within MiniShare version 1.4.1 and earlier implementations. This issue stems from inadequate input validation mechanisms within the web server component that processes HTTP POST requests. The buffer overflow occurs when the application fails to properly bounds-check incoming data, allowing malicious actors to craft specially crafted HTTP POST requests that exceed the allocated buffer space. Such vulnerabilities fall under the CWE-121 category of stack-based buffer overflow, where insufficient boundary checking permits data to overwrite adjacent memory locations. The affected MiniShare implementation processes user-supplied data without adequate sanitization, creating a pathway for attackers to manipulate memory contents and potentially execute arbitrary code on the target system. This represents a severe security weakness that directly impacts the integrity and confidentiality of systems running vulnerable versions of the software.
The technical exploitation of this vulnerability requires remote attackers to send a carefully constructed HTTP POST request containing an excessively long payload that overflows the designated buffer space. When the vulnerable application processes this malformed request, the buffer overflow can overwrite critical program variables, return addresses, or function pointers in the stack memory. Attackers can leverage this memory corruption to redirect program execution flow, potentially injecting and executing malicious code within the context of the MiniShare process. The attack vector is particularly concerning because it requires no authentication or local access, making it a remote code execution vulnerability that can be exploited from anywhere on the network. This aligns with ATT&CK technique T1203 which describes the use of malicious input to cause program execution flow to be redirected, and T1059 which covers the execution of commands through various interfaces. The vulnerability's impact is amplified by the fact that MiniShare typically runs with elevated privileges, potentially allowing attackers to gain complete system control.
The operational consequences of this vulnerability extend beyond simple code execution to encompass complete system compromise and potential data breaches. Systems running vulnerable versions of MiniShare become susceptible to unauthorized access, data exfiltration, and persistent backdoor installation by threat actors. The discontinued nature of MiniShare adds additional risk as organizations may not receive security updates or patches, leaving these systems permanently exposed to exploitation. Network administrators face significant challenges in identifying affected systems, as the vulnerability may not be immediately apparent through standard network scanning. The attack surface expands when considering that MiniShare often runs on default ports and may be accessible from untrusted networks, increasing the likelihood of successful exploitation. Organizations that have not migrated away from this software face ongoing risk of compromise, with potential impacts including unauthorized access to network resources, system enumeration, and lateral movement within compromised networks.
Mitigation strategies for CVE-2018-19862 require immediate action to address the vulnerability in affected systems. The primary recommendation involves upgrading to a supported version of MiniShare or migrating to alternative file sharing solutions that have proper security controls implemented. Organizations should also implement network segmentation to isolate systems running vulnerable software and deploy intrusion detection systems to monitor for suspicious HTTP POST traffic patterns. Input validation controls should be strengthened at network boundaries to filter out excessively long HTTP requests before they reach vulnerable applications. Security teams should conduct comprehensive vulnerability assessments to identify all systems running affected versions and establish a remediation timeline. Additionally, implementing web application firewalls can provide an additional layer of protection by monitoring and filtering HTTP traffic for known malicious patterns. The discontinuation of MiniShare means that organizations should plan for complete software replacement rather than relying on partial patches or workarounds, as the software ecosystem no longer receives security updates. Regular security monitoring and network traffic analysis should be implemented to detect potential exploitation attempts and maintain situational awareness of the threat landscape.