New Security Update for OS X

Networking/Security Forums -> Macintosh

Author: acidrainLocation: Yakima, Washington State, USA PostPosted: Tue Feb 24, 2004 10:34 am    Post subject: New Security Update for OS X
Security Update 2004-02-23 delivers a number of security enhancements and is recommended for all Macintosh users. This update includes the following components:


Additionally, Security Update 2003-11-19 has been incorporated into this security update. Those components are:

Mail w/CRAM-MD5 authentication
Personal File Sharing
QuickTime for Java
zlib "gzprintf()" function

OS X Client 10.3
OS X Client 10.2

Installed ok on my 10.2 problems noticed afterward[/quote]

Author: RoboGeekLocation: LeRoy, IL PostPosted: Wed Feb 25, 2004 3:29 pm    Post subject:
that update fixes this vulnerability:

The following security advisory can be found at the SecuriTeam web site:

- - - - - - - - -

Mac OS X pppd Format String Vulnerability


The ppp daemon that comes installed by default in Mac OS X is vulnerable
to a format string vulnerability. The vulnerability is in a function
specific to pppd that does not allow for traditional exploitation
(arbitrary data written to arbitrary memory locations) via %n. However, it
is possible to read arbitrary data out of pppd's process. Under certain
circumstances, it is also possible to 'steal' PAP/CHAP authentication


When pppd receives an invalid command line argument, it will eventually
pass it as a format specifier to vslprintf(). This function is a custom
replacement for vsnprintf(), and does contains a small subset of the
format specifiers. ?The offending function is called option_error:

option_error __V((char *fmt, ...))
va_list args;
char buf[256];

#if defined(__STDC__)
va_start(args, fmt);
char *fmt;
fmt = va_arg(args, char *);
vslprintf(buf, sizeof(buf), fmt, args);
if (phase == PHASE_INITIALIZE)
fprintf(stderr, "%s: %s\n", progname, buf);
#ifdef __APPLE__
syslog(LOG_ERR, "%s", buf);

As we can see, there is a specific Apple ifdef that will pass our buffer
directly to error().

By utilizing one of the techniques outlined in scut's paper, "Exploiting
Format String Vulnerabilities", it may be possible to access PAP and/or
CHAP credentials, if the OS X system is being used as a PPP server.

Vendor Response:
This is fixed in Security Update 2004-02-23 for Mac OS X 10.3.2 and Mac OS
X 10.2.8. Information about Apple Security Updates may be found at

Install the vendor supplied upgrade.

Common Vulnerabilities and Exposures (CVE) Information:
The Common Vulnerabilities and Exposures (CVE) project has assigned the
following names to these issues. These are candidates for inclusion in the
CVE list (, which standardizes names for security
CAN-2004-0165 Mac OS X pppd format string vulnerability.

Author: theDarkStrangerLocation: South-Texas PostPosted: Wed Feb 25, 2004 4:41 pm    Post subject:
Hi All,

I'm new to the forum but a long time reader.

Correct me if i'm wrong but isn't this Update also a fix for the tcpdump issue Mac OS X has been having to where you can get the admin password to the machine via the dump.

I could have been mistaken. It was late when I downloaded the update.


Networking/Security Forums -> Macintosh

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