MacOS X Client Apache File Protection Bypass Vulnerability
BugTraq ID: 2852
Remote: Yes
Date Published: 2001-06-10
Relevant URL:
http://www.securityfocus.com/bid/2852
Summary:

A vulnerability exists when Apache webserver is used with Mac OS X Client.

The standard filesystem for Mac OS X is HFS+. HFS+ is case insensitive
while Apache's filtering is case sensitive.

Apache offers file protection functionality which prohibits unprivileged
users from accessing protected directories.  Because it was developed on
systems with case sensitive filesystems, requests must match the filter
exactly.  Any difference in character case will cause a request to not
match the filter.

Apache will filter all file requests that match filters exactly (including
case), but it will not filter requests if the case .  Since HFS+ is case
insensitive, these requests will result in the "filtered" files being
disclosed.

The impact is that privileged files may be arbitrarily disclosed to
non-privileged remote users.

[ m�me probl�me que IIS et Apache sous Windows NT p.ex. Solution: module
open source de Apple. Semble ne concerner que la version workstation de
MacOS X ... ]


Imapd 'Local' Buffer Overflow Vulnerabilities
BugTraq ID: 2856
Remote: Yes
Date Published: 2001-06-11
Relevant URL:
http://www.securityfocus.com/bid/2856
Summary:

Washington University Imapd is a popular server program that allows
clients to download mail from servers via the IMAP protocol.

Imapd reportedly contains buffer overflow vulnerabilities which are
exploitable by authenticated clients.  These overflows may provide
malicious clients with interactive access on the host.

Imapd lowers privileges after users authenticate.  A user with shell
access on the host may not accomplish anything by exploiting this
vulnerability.  These buffer overflows should be of concern to
administrators of mail servers with IMAP users that do not have access to
the underlying host.

If one of these vulnerabilities can be exploited to execute arbitrary
code, an attacker with an IMAP-only username/password may be able to gain
access to the server host.  It is significantly easier for attackers to
compromise the entire system (gain root) if they have local access.

MandrakeSoft has released upgraded packages which will eliminate the
reported vulnerabilities.

More information is forthcoming in future updates pending complete SIA
analysis of this/these vulnberabilities.

MDBMS Query Display Buffer Overflow Vulnerability
BugTraq ID: 2867
Remote: Yes
Date Published: 2001-06-12
Relevant URL:
http://www.securityfocus.com/bid/2867
Summary:

MDBMS is a free relational database management system.

A buffer overflow condition exists in MDBMS that may allow a remote user
with database access to execute arbitrary code on a host running the
server.

The problem occurs when a user issues the '\s' command to display the
query buffer when it contains a large amount of data.  If the buffer is
approximately 10000 bytes in length or longer, the condition is triggered.

[ free comme libre ou free comme pas payant ? ]

Linux Man Page Source Buffer Overflow Vulnerability
BugTraq ID: 2872
Remote: No
Date Published: 2001-06-12
Relevant URL:
http://www.securityfocus.com/bid/2872
Summary:

A buffer overflow vulnerability exists in the implementation of the 'man'
system manual pager program commonly included with Linux distributions.

When a manual page file begins with a '.so' statement, the 'man' program
uses the filename given with the statement as the source file for that
manual page.  These statements can be specified recursively over several
manual page files; the program loads each sourced file until the
'ultimate' file is found.

A subtle bug exists in the algorithm used to handle these files.  If a
manual page file is compressed by a program such as gzip, the man program
must first expand the file to check the first line for the '.so'
statement.  To do this, it calls popen() to execute the expansion program,
passing the manual page filename as part of the command line.


The boundary condition error occurs because the source file algorithm
concatenates data from '.so' statements into a fixed-sized buffer for
every level of recursion.  If a command inserted after shell
metacharacters in the filename returns a '.SO' statement of excessive
length, the recursive nature of the algorithm could trigger the condition.

As a result, local users can use this vulnerability to execute arbitrary
code/commands with group 'man' privileges.  This can lead to further
system compromise.

Multiple BSD Vendor Ptrace Race Condition Vulnerability
BugTraq ID: 2873
Remote: No
Date Published: 2001-06-14
Relevant URL:
http://www.securityfocus.com/bid/2873
Summary:

Ptrace is a facility used mostly by debuggers that allows one process to
attach to another and monitor/modify its execution state and memory.

Ptrace implements checks to ensure that unprivileged processes do not
attach to privileged ones.  It has been reported that a race condition
exists in some BSD ptrace implementations that may cause these checks to
by bypassed.

The race condition is reportedly present when a process is exec()ing a
setuid image.  It may be possible to attach to the setuid process if the
race is won.

Once an unprivileged process has attached to a setuid process, it is
possible to cause resumption of the setuid process' execution at an
arbitrary address.  If attacker-supplied instructions exist in an
executable region of the setuid process' memory (such as in the
environment), the attacker may resume execution at the location of these
instructions.  These instructions will then execute with the enhanced
privileges of the setuid process.

The attaching process may also be able to modify memory belonging to the
setuid process.  This provides the attacker with almost complete control
over the setuid process.

If exploited, this vulnerability could lead to local attackers elevating
privileges.  The privileges that can be gained depend on the setuid
programs installed on the system.

OpenBSD and NetBSD have both confirmed that they are vulnerable.  OpenBSD
has released kernel patches, while NetBSD has fixed the problem in their
CVS tree.

Updates will be sent out as more information becomes available.


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