Executive brief
Netatalk is an open-source implementation of the Apple Filing Protocol (AFP), which allows Unix-like systems to serve files to macOS clients. A security flaw in how the software handles file names can allow a logged-in user to crash the file server or potentially gain unauthorized control over the system. This could lead to a disruption of file-sharing services or the exposure of sensitive data stored on the server.
Technical details
A stack-based buffer overflow exists in Netatalk's 'convert_charset()' function, specifically during Unicode filename conversion. The vulnerability is caused by a type confusion issue involving UCS-2 character sequences where null terminators can be written at twice the intended byte offset when processing decomposing character sequences. This memory corruption can be triggered by an authenticated client over the network. While the most immediate impact is a process crash (DoS), the nature of the stack overflow suggests that arbitrary code execution or broader memory corruption may be possible. The issue is resolved in version 4.4.3.
Affected products
- Netatalk Team Netatalk 2.0.4 through 4.4.2
Timeline
- 2026-05-13: disclosed: Initial disclosure date reported by vendor
- 2026-05-21: advisory: NVD publication date
- 2026-05-21: patched: Fixed in version 4.4.3