CVE-2026-44051

A heap-based buffer overflow in the CNID daemon in Netatalk (versions 2.0.0-4.4.2) allows a remote authenticated attacker to execute arbitrary code with elevated privileges or cause a denial of service.

Netatalk versions 3.1.19 through 4.4.2 contain a stack-based buffer overflow in the deletedir() function of the afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. This allows unauthenticated attackers to perform an unbounded strcpy() operation with attacker-controlled filenames into a nearly full stack buffer. Version 4.4.3 patches the issue.

Netatalk is a Free and Open Source file server suite for Unix-like operating systems. In versions 3.1.19 through 4.4.2, a stack-based buffer overflow exists in the copydir() function of Netatalk's afpd daemon due to an integer underflow in the calculation of the remaining buffer size used for path construction. copydir() is a utility function called when a file operation crosses a device boundary inside an AFP shared volume, which the standard library's renameat() cannot handle. The function attempts to track available buffer space using srem and drem for source and destination paths. Incorrect arithmetic causes both srem and drem to underflow to SIZE_MAX. Consequently, boundary checks against strlen(de->d_name) always pass, allowing strcpy() to append filenames into nearly full stack buffers. Version 4.4.3 patches the issue. As a workaround, configure each AFP shared volume to be structured as a single file system, in other words no subdirectory of a shared volume should be a mount point for a different file system.

An incorrectly placed cast from bytes to int allowed for server-side panic in the AES-GCM packet decoder for well-crafted inputs.

A time-of-check time-of-use (TOCTOU) condition in the ad_flush function in Netatalk 3.0.0 through 4.4.2 involves root-privileged file operations, potentially allowing a remote attacker to cause limited data modification under specific race conditions.

A missing break statement in DSI OpenSession processing in Netatalk 1.5.0 through 4.4.2 causes a fall-through from DSIOPT_ATTNQUANT to DSIOPT_SERVQUANT. A remote attacker can cause minor service disruption via crafted DSI session options.

Netatalk 2.1.0 through 4.4.2 combines multiple errno values using bitwise OR, resulting in incorrect error codes when multiple errors occur. A remote attacker can cause minor service disruption via conditions triggering incorrect error handling.

Netatalk versions 3.1.2 through 4.4.2 are compiled without FORTIFY_SOURCE, disabling built-in buffer overflow detection. A remote attacker can cause a minor denial of service via memory errors that would otherwise be safely terminated.

In Netatalk versions 3.0.0 through 4.4.2, a dead bounds check in the Spotlight RPC unmarshaller provides no effective bounds protection, potentially allowing a remote authenticated attacker to obtain limited information via crafted Spotlight RPC requests.

In Netatalk versions 2.0.0 through 4.4.2, an incorrect calculation in the hextoint macro due to improper uppercase character handling allows a remote authenticated attacker to cause limited data modification via crafted hexadecimal input.