Executive brief
FileRun is a self-hosted file manager and sharing platform. A critical vulnerability in how FileRun handles shell command escaping allows attackers to inject arbitrary OS commands, potentially leading to full server compromise. Superuser-level attackers can exploit this directly through settings endpoints, while other attackers can store malicious payloads that execute when video thumbnails are generated, affecting all users.
Technical details
FileRun redefines PHP's escapeshellcmd() function as a no-op in CLI.php, effectively disabling shell metacharacter escaping. This allows attacker-controlled input to reach exec() sinks unsanitized. The vulnerability can be exploited through two paths: (1) an interactive attack via image_preview.php with a crafted args parameter, requiring superuser authentication, or (2) a persistent attack by injecting malicious payloads into thumbnails_ffmpeg_args or thumbnails_ffmpeg_ss configuration fields, which then execute when any user triggers video thumbnail generation. The root cause is the neutralization of a critical security function that should prevent shell injection. FileRun 2026.3.0 patches this vulnerability; versions before 2026.3.0 are affected.
Affected products
- FileRun FileRun before 2026.3.0
Timeline
- 2026-09-10: disclosed
- 2026-09-06: patched: Fixed in FileRun 2026.3.0