Executive brief
Netatalk is an open-source implementation of the Apple Filing Protocol (AFP) used to allow Linux and Unix systems to act as file servers for macOS clients. A vulnerability in how the software handles legacy AppleTalk session IDs allows an unauthenticated attacker on the same local network to crash the file sharing service. This could lead to a loss of availability for users relying on the server for file storage and access.
Technical details
An out-of-bounds read (CWE-125) exists in Netatalk's legacy ASP/DDP session handling. The vulnerability is caused by using an attacker-controlled ASP session ID as an array index without validating it against the session table size. An unauthenticated attacker on an adjacent network can exploit this to cause a service crash (Denial of Service) or potentially achieve remote code execution, though the latter is less certain. The issue affects versions 1.3 through 4.4.2 and is fixed in version 4.4.3. Administrators can mitigate the risk by disabling AppleTalk support in the configuration.
Affected products
- Netatalk Netatalk 1.3 through 4.4.2
Timeline
- 2026-05-13: disclosed
- 2026-05-21: advisory: NVD publication date
- 2026-05-21: patched: Fixed in version 4.4.3