search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Apple Mac OS X AppleFileServer fails to properly handle certain authentication requests

Vulnerability Note VU#648406

Original Release Date: 2004-05-07 | Last Revised: 2004-05-07


There is a buffer overflow vulnerability in the way Apple's AppleFileServer handles certain authentication requests. This vulnerability could allow an unauthenticated, remote attacker to execute arbitrary code.


The AppleFileServer provides Apple Filing Protocol (AFP) services for clients and servers. This protocol allows users to share files over the network. By default the AFP service is not enabled. There is a buffer overflow vulnerability in the way the AppleFileServer handles certain authentication requests. By supplying a specially crafted PathName argument during authentication, an unauthenticated, remote attacker could execute arbitrary code.

According to the @stake advisory:
There is a pre-authentication, remotely exploitable stack buffer overflow that allows an attacker to obtain administrative privileges. The overflow occurs when parsing the PathName argument from LoginExt packet requesting authentication using the Cleartext Password User Authentication Method (UAM). The PathName argument is encoded as one-byte specifying the string type, two-bytes specifying the string length, and finally the string itself. A string of type AFPName (0x3) that is longer than the length declared in the packet will overflow the fixed-size stack buffer.


An unauthenticated, remote attacker could execute arbitrary code.


Apply Patch

Apple has issued an advisory to address this issue. For further details, please see the Apple Security Advisory (Security Update 2004-05-03).

Disable AppleFileServer

Until a patch can be applied, you may wish to disable the AppleFileServer.

Vendor Information


Apple Computer Inc. Affected

Updated:  May 07, 2004



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


Please refer to Apple Security Advisory: APPLE-SA-2004-05-03 Security Update 2004-05-03.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector



This vulnerability was reported by Dave G. of @stake.

This document was written by Damon Morda based on information in the @stake advisory.

Other Information

CVE IDs: CVE-2004-0430
Severity Metric: 27.42
Date Public: 2004-05-03
Date First Published: 2004-05-07
Date Last Updated: 2004-05-07 15:43 UTC
Document Revision: 26

Sponsored by CISA.