CVE-2026-54337 in Fireshare
Summary
by MITRE • 09/15/2026
Fireshare facilitates self-hosted media and link sharing. Prior to version 1.6.14, an argument Injection in the video upload function allows unauthenticated attacker to write/overwrite system files. Version 1.6.14 fixes the issue.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified in Fireshare prior to version 1.6.14 represents a critical security flaw rooted in improper input validation within the application's video upload functionality. As a self-hosted media and link sharing platform, Fireshare processes user-uploaded content for storage and distribution. The specific weakness lies in how the backend handles file paths or arguments associated with uploaded videos. An unauthenticated attacker can exploit this by injecting malicious command-line arguments into the input fields used during the upload process. This type of flaw is classically categorized under CWE-78, which defines Improper Neutralization of Special Elements used in an OS Command, commonly known as Operating System Command Injection. The root cause typically involves the application constructing system commands using unsanitized user-supplied data without adequate filtering or escaping mechanisms to prevent the execution of unintended operations.
The operational impact of this vulnerability is severe due to its unauthenticated nature and potential for arbitrary file write access. By successfully injecting arguments, an attacker can manipulate the underlying operating system's behavior during the video processing phase. This capability allows the attacker to specify target paths that are outside the intended upload directory, effectively enabling them to write or overwrite critical system files on the host server. Such actions can lead to complete compromise of the underlying infrastructure, including the installation of backdoors, modification of configuration files to redirect traffic, or deletion of essential system components leading to denial of service. The ability to overwrite arbitrary files bypasses standard access controls since the application often runs with elevated privileges necessary for media processing tasks, thereby amplifying the risk profile significantly.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK technique T1059, Command and Scripting Interpreter, specifically sub-techniques involving shell commands or system utilities. The attack vector is remote and unauthenticated, which corresponds to high exploitability metrics in standard scoring frameworks like CVSS. Attackers can leverage automated tools to probe for this weakness by sending crafted HTTP requests with malicious payloads embedded in the file upload parameters. Once executed, these payloads allow lateral movement within the server environment or persistence mechanisms that survive application restarts if critical system files are modified. The lack of authentication requirement makes this vulnerability particularly dangerous as it does not require valid credentials, exposing any instance running a vulnerable version to immediate exploitation by automated scanners on the internet.
Mitigation strategies must prioritize upgrading the Fireshare installation to version 1.6.14 or later, where the developers have implemented fixes for this argument injection flaw. In addition to patching, administrators should enforce strict input validation and sanitization practices in any custom integrations or future development cycles. Implementing a Web Application Firewall can provide an additional layer of defense by detecting and blocking known command injection patterns in HTTP requests. Furthermore, running the application with the principle of least privilege is essential; ensuring that the process user has minimal permissions to write only to designated media directories reduces the impact even if exploitation occurs. Regular security audits and static code analysis tools should be employed to identify similar vulnerabilities in other parts of the application logic before they can be exploited by malicious actors seeking to compromise self-hosted services.