CVE-2025-46394 is a vulnerability identified in the tar utility component of BusyBox, a widely used software suite that provides several Unix utilities in a single executable, commonly deployed in embedded systems and lightweight Linux distributions. The vulnerability is classified under CWE-451, which pertains to User Interface (UI) Misrepresentation of Critical Information. Specifically, this flaw allows a TAR archive to contain filenames that are hidden from directory listings by exploiting terminal escape sequences. Terminal escape sequences are special character sequences that control cursor movement, color, and other output formatting on terminal displays. By embedding these sequences within filenames, an attacker can manipulate how file listings appear, effectively concealing certain files from users when they perform a directory listing using tar. This misrepresentation can lead to users being unaware of the presence of certain files within an archive, potentially hiding malicious payloads or critical files that should be inspected or removed. The vulnerability affects BusyBox versions up to and including 1.37.0. No public exploits have been reported in the wild as of the publication date (April 23, 2025), and no patches or fixes have been linked yet. The issue arises from insufficient sanitization or handling of terminal escape sequences in filenames during the tar listing process, leading to a UI-level deception rather than direct code execution or privilege escalation. This vulnerability primarily impacts the integrity and confidentiality of information by misleading users about the contents of archives, which can facilitate further attacks such as the introduction of malicious files or evasion of security controls relying on file visibility.

For European organizations, the impact of CVE-2025-46394 can be significant, especially in sectors relying heavily on embedded systems, IoT devices, or lightweight Linux distributions that incorporate BusyBox. The ability to hide files within TAR archives can be exploited by threat actors to smuggle malicious payloads or sensitive data unnoticed, undermining trust in software supply chains and archival integrity. This can lead to undetected malware deployment, data exfiltration, or persistence mechanisms within critical infrastructure, industrial control systems, or enterprise environments. Since BusyBox is prevalent in network equipment, routers, and various embedded devices, the vulnerability could facilitate stealthy attacks that evade detection by system administrators or automated scanning tools that rely on file listings. Additionally, the UI misrepresentation can complicate incident response and forensic analysis, delaying detection and remediation efforts. While the vulnerability does not directly enable code execution, the indirect consequences of hidden malicious files can be severe. European organizations in telecommunications, manufacturing, and critical infrastructure sectors are particularly at risk due to their reliance on embedded systems. The lack of known exploits currently reduces immediate risk, but the potential for future exploitation necessitates proactive measures.

To mitigate CVE-2025-46394, European organizations should implement several specific actions beyond generic patching advice: 1) Monitor BusyBox usage across all embedded and lightweight Linux systems, identifying versions up to 1.37.0 that are vulnerable. 2) Where possible, replace or upgrade BusyBox tar utilities with versions that sanitize or neutralize terminal escape sequences in filenames, or apply vendor patches once available. 3) Implement additional validation and inspection of TAR archives using alternative tools that do not interpret terminal escape sequences or that provide raw filename outputs to detect hidden files. 4) Enhance logging and monitoring to flag suspicious TAR archives, especially those containing unusual or non-printable characters in filenames. 5) Educate system administrators and incident responders about this UI misrepresentation technique to improve detection during manual reviews. 6) For critical embedded devices, consider deploying integrity verification mechanisms that check archive contents against known baselines, preventing unauthorized or hidden file insertions. 7) Collaborate with vendors and open-source communities to accelerate patch development and dissemination. 8) In environments where BusyBox cannot be updated promptly, restrict TAR archive usage to trusted sources and implement network segmentation to limit potential attack vectors.