March 2005

ID: 00251
Ref: 230/05
Date: 29 March 2005:16:49:53
Version: 1

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Title: Sun - Buffer Overflow in telnet(1) Client Software (57755)
Abstract: If a remote unprivileged user is able to cause a user to execute the telnet(1) utility on their client system, then that remote user may be able to execute arbitrary commands on the client system with the privileges of the user who executed telnet(1).
Vendors affected: Sun
Operating systems affected: Sun
Applications affected: Sun

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Title
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Sun - Buffer Overflow in telnet(1) Client Software (57755)


Detail
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PLEASE NOTE- The following is a plain text copy of a Sun SunSolve web page,
which is located at:
http://sunsolve.sun.com/search/printfriendly.do?assetkey=1-26-57755-1



Document Audience: PUBLIC
Document ID: 57755
Title: Document ID 57755
Synopsis: Buffer Overflow in telnet(1) Client Software
Update Date: 2005-03-28

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Description
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Sun(sm) Alert Notification

Sun Alert ID: 57755
Synopsis: Buffer Overflow in telnet(1) Client Software
Category: Security
Product: Solaris
BugIDs: 6234932
Avoidance: Workaround
State: Committed
Date Released: 28-Mar-2005
Date Closed:
Date Modified:


1. Impact There is a buffer overflow in the unprivileged telnet(1) utility. This
is not a security vulnerability on its own. However, telnet(1) communicates with
another host using the TELNET protocol and thus there is a small risk of a remote
user successfully exploiting the overflow.

If a remote unprivileged user is able to cause a user to execute the telnet(1)
utility on their client system, then that remote user may be able to execute
arbitrary commands on the client system with the privileges of the user who
executed telnet(1).

This issue is described in CAN-2005-0469 at
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-0469

Sun acknowledges with thanks, iDEFENSE (http://www.idefense.com), for bringing
this issue to our attention. This issue is also referenced in the following iDEFENSE
documents:

IDEF0866 - Multiple Telnet Client slc_add_reply() Buffer Overflow

IDEF0867 - Multiple Telnet Client env_opt_add() Buffer Overflow

which can be found at:
http://www.idefense.com/application/poi/display?type=vulnerabilities (3.28.05)


2. Contributing Factors This issue can occur in the following releases:

SPARC Platform

Solaris 7
Solaris 8
Solaris 9
Solaris 10
x86 Platform

Solaris 7
Solaris 8
Solaris 9
Solaris 10


3. Symptoms There are no predictable symptoms that would indicate the described issue
has been exploited.

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Solution Summary
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4. Relief/Workaround To work around the described issue until patches are available,
sites may consider removing the execute permissions from the Solaris telnet(1) utility.
To accomplish this, the following command can be run (as "root"):

# chmod 000 /usr/bin/telnet

To restore the original permissions to the telnet(1) utility (after the patches have been
applied) the following command can be run (as "root"):

# chmod 555 /usr/bin/telnet

5. Resolution A final resolution is pending completion.

This Sun Alert notification is being provided to you on an "AS IS" basis. This Sun Alert
notification may contain information provided by third parties. The issues described in
this Sun Alert notification may or may not impact your system(s). Sun makes no
representations, warranties, or guarantees as to the information contained herein. ANY
AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE HEREBY DISCLAIMED.
BY ACCESSING THIS DOCUMENT YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE OUT OF YOUR
USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN. This Sun Alert notification contains
Sun proprietary and confidential information. It is being provided to you pursuant to the
provisions of your agreement to purchase services from Sun, or, if you do not have such an
agreement, the Sun.com Terms of Use. This Sun Alert notification may only be used for the
purposes contemplated by these agreements.

Copyright 2000-2005 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054
U.S.A. All rights reserved.

Applies To
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Attachments
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