Netatalk Security Advisory

Subject NULL-pointer dereference in Spotlight CNID array handling
CVE ID# CVE-2026-110780
Severity Moderate
Disclosure Date 2026/10/15
Affected Versions 3.1.0-4.5.1
Summary Spotlight RPC handlers access the first CNID array element without checking that the array is nonempty

Description

sl_rpc_fetchAttributeNamesForOIDArray(), sl_rpc_storeAttributesForOIDArray(), and sl_rpc_fetchAttributesForOIDArray() in etc/afpd/spotlight.c dereference an empty CNID array accepted by the unmarshaller, causing a NULL-pointer dereference (CWE-476). A crafted FPSpotlightRPC request with an outer CNID length greater than 16 and an inner count of zero triggers the crash. Exploitation requires Spotlight support to be built and enabled, and an authenticated client with an accessible volume open. Guest access is sufficient when the optional guest UAM and a guest-accessible volume are configured.

The crash terminates the afpd worker handling the connection. In the default configuration, each connection has its own child process, limiting the demonstrated denial of service to the attacker’s session. No memory write or code execution has been established.

Patch Availability

Apply CVE-2026-110780.patch to a Netatalk 4.5.1 source tree to hotfix your local Netatalk deployment.

Upgrade to Netatalk 4.5.2 or later, which includes the fix.

CVSS Calculation

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (5.3)

Workaround

Disable Spotlight indexing in afp.conf:

[Global]
spotlight = no

Credits

Vulnerability reported by:

Elias Hasas (@zer0d4y5)

Patch developed by:

Daniel Markstedt of the Netatalk team

References


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