Opened 9 hours ago

#13245 new Bug report

FileZilla Server 1.10.3 crashes when RETR’ing a specific JPEG file (20.S25-041119.jpg)

Reported by: Daniel Owned by:
Priority: high Component: FileZilla Server
Keywords: Crash, specific file Cc: Daniel
Component version: 1.10.3 Operating system type: Windows
Operating system version: Windows Server 2019

Description

Environment
FileZilla Server version: 1.10.3 (latest stable)
OS: Windows Server 2019 / Windows 10
Connection: Explicit FTP over TLS enabled; Passive Mode using EPSV (and PASV fallback tested)

Clients Tested
n8n FTP Node (basic-ftp library) — download of this file triggers server crash
curl with --disable-epsv — download still crashes the server
Windows built-in ftp client (with passive then get) — successfully retrieves the file

Descrition
When attempting to download (RETR) the file 20.S25-041119.jpg, the FileZilla Server process terminates unexpectedly (service restarts) within the data transfer phase. No “226 Transfer complete” reply is ever sent. The same transfer of other files (including other JPEGs) succeeds reliably. Changing the filename or extension to .txt does not avoid the crash; however, compressing the file into a ZIP container makes the transfer succeed.

Relevant Log Excerpt

2025-05-09T11:46:32.454Z >> RETR /Zoder/Ausgang/POD/20.S25-041119.jpg
2025-05-09T11:46:32.454Z << 150 Starting data transfer.
no subsequent “226 Transfer complete”
2025-05-09T11:53:37.570Z == ===== FileZilla Server 1.10.3 new logging started =====

Notes & Hypothesis
The crash is deterministic for this exact byte-pattern; renaming the file does not help.

Zipping the file (changing its binary stream) bypasses the bug, pointing to a corner-case in the VFS streaming code.

Attachments (2)

20.S25-041119.txt (150.0 KB ) - added by Daniel 9 hours ago.
JPG-File as .TXT
20.S25-041119.jpg (150.0 KB ) - added by Daniel 9 hours ago.
the jpg that crashes the server

Download all attachments as: .zip

Change History (2)

by Daniel, 9 hours ago

Attachment: 20.S25-041119.txt added

JPG-File as .TXT

by Daniel, 9 hours ago

Attachment: 20.S25-041119.jpg added

the jpg that crashes the server

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