Date: Wed, 19 Apr 2000 12:50:04 -0400
From: [email protected]
To: [email protected]Subject: Cisco Security Advisory: Cisco Catalyst Enable Password Bypass Vulnerability
-----BEGIN PGP SIGNED MESSAGE-----
Cisco Catalyst Enable Password Bypass Vulnerability
Revision 1.1
Tentatively for release 2000 April 19 08:00 AM US/Pacific (UTC+0700)
---------------------------------------------------------------------------
Summary
=======
Cisco Catalyst software permits unauthorized access to the enable mode in
the 5.4(1) release. Once initial access is granted, access can be obtained
for the higher level "enable" mode without a password. This problem is
resolved in version 5.4(2). Customers with vulnerable releases are urged to
upgrade as soon as possible.
This vulnerability has been assigned Cisco bug ID CSCdr10025.
Affected Products
=================
All users of Cisco Catalyst 4000, 5000, 5500, 6000 and 6500 with the
software version 5.4(1) only.
The affected image names are as follows:
cat4000_5-4-1.bin
cat5000-supg_5-4-1.bin
cat5000-Sup_5-4-1.bin
cat5000-Sup3_5-4-1.bin
cat6000-Sup_5-4-1.bin
No other releases of Cisco Catalyst software are affected by this
vulnerability.
No other Cisco products are affected by this vulnerability.
Details
=======
Anyone who can obtain ordinary console access to an affected switch can
bypass password authentication to obtain "enable" mode access without
knowledge of the "enable" password. This vulnerability can be exploited
through the network using telnet or via the physical console.
This problem was introduced in software version 5.4(1), and is corrected in
version 5.4(2). Due to this defect, software version 5.4(1) is deferred.
Customers are urged to upgrade to version 5.4(2).
Impact
======
This vulnerability permits unauthorized access to the configuration mode and
unauthorized configuration changes on a Catalyst switch.
Software Versions and Fixes
Getting Fixed Software
Cisco is offering free software upgrades to remedy this vulnerability for
all affected customers.
Customers with contracts should obtain upgraded software through their
regular update channels. For most customers, this means that upgrades should
be obtained via the Software Center on Cisco's Worldwide Web site at
http://www.cisco.com.
Customers without contracts should get their upgrades by contacting the
Cisco Technical Assistance Center (TAC). TAC contacts are as follows:
* +1 800 553 2447 (toll-free from within North America)
* +1 408 526 7209 (toll call from anywhere in the world)
* e-mail: [email protected]
Give the URL of this notice as evidence of your entitlement to a free
upgrade. Free upgrades for non-contract customers must be requested through
the TAC. Please do not contact either "[email protected]" or
"[email protected]" for software upgrades.
Workarounds
===========
There are no known workarounds for this vulnerability. Strictly limiting
telnet access to the device will prevent the initial connection required to
exploit this vulnerability. Telnet access can be controlled with the
following command set:
set ip permit <address> <mask> telnet
set ip permit enable
This command set will deny all traffic not specified in the permit
statement.
Exploitation and Public Announcements
Cisco Systems knows of no public discussion nor active exploits involving
this vulnerability, which was reported by several customers who encountered
it during normal use.
Status of This Notice: FINAL
This is a final notice. Although Cisco cannot guarantee the accuracy of all
statements in this notice, all of the facts have been checked to the best of
our ability. Cisco does not anticipate issuing updated versions of this
notice unless there is some material change in the facts. Should there be a
significant change in the facts, Cisco may update this notice.
Distribution
============
This notice will be posted on Cisco's Worldwide Web site
at http://www.cisco.com/warp/public/707/catos-enable-bypass-pub.shtml. In
addition to Worldwide Web posting, a text version of this notice is
clear-signed with the Cisco PSIRT PGP key and is posted to the following
e-mail and Usenet news recipients:
* [email protected]
* [email protected]
* [email protected] (includes CERT/CC)
* [email protected]
* comp.dcom.sys.cisco
* Various internal Cisco mailing lists
Future updates of this notice, if any, will be placed on Cisco's Worldwide
Web server, but may or may not be actively announced on mailing lists or
newsgroups. Users concerned about this problem are encouraged to check the
URL given above for any updates.
Revision History
================
Revision 1.0 For public release 19-APR-2000 08:00 AM US/Pacific (UTC+0700)
Revision 1.1 For public release 19-APR-2000 08:00 AM US/Pacific (UTC+0700)
Cisco Security Procedures
Complete information on reporting security vulnerabilities in Cisco
products, obtaining assistance with security incidents, and registering to
receive security information from Cisco, is available on Cisco's Worldwide
Web site at
http://www.cisco.com/warp/public/707/sec_incident_response.shtml. This
includes instructions for press inquiries regarding Cisco security notices.
---------------------------------------------------------------------------
This notice is copyright 2000 by Cisco Systems, Inc. This notice may be
redistributed freely after the release date given at the top of the text,
provided that redistributed copies are complete and unmodified, including
all date and version information.
---------------------------------------------------------------------------
All contents copyright ╘ 1992--2000 Cisco Systems Inc. Important Notices and
Privacy Statement.
-----BEGIN PGP SIGNATURE-----
Version: PGP 6.5.2
iQEVAwUBOP3f/GiN3BRdFxkbAQFQ5wgAlFcwEtxZYuXoM5sGx4wrDeuB2ifijcAR
TOTV1h/9vdezM24LO6hdipi0E7ekS5YvLJI8dICeths4uR+Hyq4r/X7yo21FSner
kZXaW2BTZlSTvv09p94CtpUZI9SFjXhM9uTRTUlgg3gODl3U+e+nsKc9c7QMM3Ab
YhZUTsXhdcMDEpRtGkXgO5hqZhNL7bOxNiUP02OgEr16BwwpJsKGAomEPgwOpozl
P32YCo2WHUOmWUuOT4Rdju/oPVfc4q6FhbzbS2H9YsfNRU7qV43gj7AhfKalqY4t
k5p0Zd9Ar7jwwpbIHdLbMVp9ph3OhDLxG+H9T438wKZNBbjQikPPyA==
=+8jj
-----END PGP SIGNATURE-----
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: PGP 6.5.2
mQENAzhQ8qUCYQEIALshjezuQIzQT3zZrKrQit2HTNarH8iba6HLdN2niIDGW9LN
ShhH0kPdD57EeOAkO2ccNvgY4HvJESgykBS6z86HULeiSVMv89TfQsKOv34cczYm
BeYtcfbgkm4MM/37UjFxUGAIoOxVX/bzya/tegiYPAaTsOcaonxqaOds/kLIR32S
/+3vcV6tu9QiiLwdKAGSN+KkrREP3qTFzKxmus1DKFz5o03yDMtYGplRQ62iae21
I8NbQtVXvARN5bdG5+4KaqI9hsT/tz8dh8OgapdaD6ht0qkY8J2DGIa1xnai4Vbe
hoz7Vozf65LErlbRWBVAn6XBD3qtaI3cFF0XGRsABRG0R0Npc2NvIFN5c3RlbXMg
UHJvZHVjdCBTZWN1cml0eSBJbmNpZGVudCBSZXNwb25zZSBUZWFtIDxwc2lydEBj
aXNjby5jb20+iQEVAwUQOFDypWiN3BRdFxkbAQEVgAf/Qins/ms1PNhD4ucJyGCY
V60wz6hQX5FXCKxewSxPOMOxkbQeiNxqENYldTwH6RZ2eVXYJX0PKZjhUmpQCwg7
aYQUv8GeROxQYlJx/j2FKmQcjIWLHQZImb7FxTFt0rgcCJI+ChGu8U3IqOmyeBmE
44qXxU/IGhJaXj8jIkSUxeKFQtI9JSxsfNiqX8itjeJlYTF8Y1MnTiuhikM3y7JM
sQFzrKSzhzfPcc3RqDAtbwYtvmb+6/9IGkHks2hox5ltJZ5v2c4lbReEpmLweDSf
enojuPPoPug8zRS/xa1uHzSZ3XKQwLWfjwZwGMzTTHOAiMWo6wlbhNnR4LlN/upv
uIkARgQQEQIABgUCOFDzRAAKCRBwkpqcbcMYIVfZAJ4z5xm+IJuj+byK+gNsNY7X
FK4THgCfS0n95c/Gxvu9tOvRFH+uwQh2dgGJAHUDBRA4UPNs3nAfbKMmz4kBAejY
AvoD771l0JZWwf5XmoCWLL0ChzbdFJqTsnd2zG4jGr1J91dkES4YDir4itqyWVRA
VFzalYCYouNPhOJZKLXUphQnAQ7x74cDznEw+MYT9eavbYcSeKkBZNEdjE3vf67x
4fSJAJUDBRA4UP5XwAV6rQ+eJbkBAX2CA/9GPlvk9EWTS54M6uTJCtC/6Bcx7phz
InAUYEX7gjlBmNF7MdIy1UdUsNL2rTdR26peB6VwzT6uXRG+RbhpGVvfHdEmJ2ec
brKaUmFisrVWB7Ho9NOo72xTru7GeJxGHb0xRcsDMCIYfyOCMvbr6lxMMAcD9zx3
nMx4VDJ7RfSStrRQQ2lzY28gU3lzdGVtcyBQcm9kdWN0IFNlY3VyaXR5IEluY2lk
ZW50IFJlc3BvbnNlIFRlYW0gPHNlY3VyaXR5LWFsZXJ0QGNpc2NvLmNvbT6JARUD
BRA4UPL6aI3cFF0XGRsBAdYKCACIhd2yDPXITE2pQzukNo+jxrMeSnqvl4DUoP6f
Ai64KLGYAqo+ZWuyFd1JLT5CtsaWuLXEBvt/9SevI/qbN18c9eSBko3wNcO49C+T
s0uttahHplxMgArqTK8y1u35C7QUz0T9xRLPaKvXYARw3/wFdaPQYehrVWBThbxk
KxJuamT3OT5uB7NgtkHK1nHpxuATj39EnvZSUTWe45ZBVulduGMG7grYRCQJ1jrG
2Ei0FO/adFKZU6DxSygwjWCM9Fdh/dncs00G7tXW8fpfIRmdsVZuYIQ7HPkoiUJF
87Hw+mdkZHiTAhPMuNO9AamZsIF65QcD4vera/zOXwU+MUcaiQBGBBARAgAGBQI4
UPNYAAoJEHCSmpxtwxghi9gAn12vk1AazXrc9GVCdXC5oFpi1TmlAJ9BsHkWwGUr
mLSAE3OE70LjxHHhDokAdQMFEDhQ84DecB9soybPiQEB2NoC/jSF5glFC5jfYjAp
VMiZHgGZDA49lcf/VZDz7ZeJAkOtZZHzlycVAlCukLl0sXfIhgygmWj6WQPPIF2z
COEjVgR625CRbYhrqC0H9ieWYJ3fu7GILoEb200GbSgUZifvq4kAlQMFEDhQ/mvA
BXqtD54luQEBWzAD/31F6aic5ZV/u6HY/ChORildURolK8LfNTwwsmwN32ZcJOUb
gSsU5cafE5XGaWvgVrPVKwAH9DFcviElBK+n7fhw+SRS5x+Ar8tZMKEgP5I9yIZX
DHwNZmFdpmk95xoK4TvCd3iyj23HcaoAGroRtuVrv5UtBG9P+FDMxScgO/cR
=sJ3p
-----END PGP PUBLIC KEY BLOCK-----
