CVE-2025-58438 is a critical path traversal vulnerability (CWE-22) identified in the internetarchive Python library and CLI tool developed by jjjake, specifically in versions 5.5.0 and below. The vulnerability resides in the File.download() method, which fails to properly sanitize user-supplied filenames or validate the final download path. This improper limitation allows an attacker to craft filenames containing path traversal sequences such as "../../../../windows/system32/file.txt" or other illegal characters. When processed, these filenames can cause files to be written outside the intended download directory, potentially overwriting critical system or application files. The impact of this vulnerability depends on the context in which the library is used but can include denial of service (by corrupting essential files), privilege escalation (by overwriting configuration files or binaries), or even remote code execution if malicious files are placed in executable paths. While the vulnerability affects all operating systems, it is particularly critical on Windows due to the potential to overwrite sensitive system files like those in the System32 directory. The vulnerability has a CVSS 4.0 base score of 9.4, indicating a critical severity with network attack vector, no privileges required, no user interaction needed, and high impact on confidentiality, integrity, and availability. The issue was published on September 6, 2025, and fixed in version 5.5.1 of the internetarchive library. No known exploits are currently reported in the wild. This vulnerability highlights the risks of inadequate input validation in file handling functions within widely used libraries, which can be leveraged by attackers to compromise systems remotely without authentication.

For European organizations, the impact of CVE-2025-58438 can be significant, especially those relying on the internetarchive library for automation or integration with Archive.org services. The ability to overwrite arbitrary files on affected systems can lead to severe operational disruptions, data loss, and potential compromise of sensitive information. Organizations using Windows-based infrastructure are at heightened risk due to the possibility of overwriting critical system files, which could result in system instability or privilege escalation. This could affect sectors such as media, research institutions, libraries, and any enterprise leveraging Archive.org data for archival or analytical purposes. Additionally, the vulnerability could be exploited to implant persistent backdoors or disrupt services, impacting availability and trustworthiness of systems. Given the network-exploitable nature and lack of required privileges or user interaction, attackers could automate exploitation at scale, potentially targeting European organizations with high dependency on this library. The absence of known exploits in the wild currently provides a window for proactive mitigation, but the critical severity score underscores the urgency for patching and risk management.

European organizations should immediately upgrade the internetarchive library to version 5.5.1 or later, where the vulnerability is fixed. For environments where immediate upgrade is not feasible, implement strict input validation and sanitization on filenames before passing them to the File.download() method, ensuring removal of any path traversal sequences or illegal characters. Employ application-level sandboxing or containerization to limit the file system scope accessible to the library, reducing the impact of potential exploitation. Monitor file system changes in directories used by the library for unexpected or unauthorized modifications. Incorporate runtime application self-protection (RASP) or endpoint detection and response (EDR) solutions to detect anomalous file writes or privilege escalations. Conduct code audits for any custom wrappers or integrations around the internetarchive library to ensure no additional unsafe file handling occurs. Finally, maintain an inventory of all systems using this library to prioritize patching and risk assessment, and educate developers and system administrators about the risks of path traversal vulnerabilities.