exploit the possibilities
Home Files News &[SERVICES_TAB]About Contact Add New

cisco.00-12-06.memleak

cisco.00-12-06.memleak
Posted Dec 7, 2000
Site cisco.com

Cisco Security Advisory - Catalyst Memory Leak Vulnerability. A series of failed telnet authentication attempts to the switch can cause the Catalyst Switch to fail to pass traffic or accept management connections until the system is rebooted or a power cycle is performed. All types of telnet authentication are affected, including Kerberized telnet, and AAA authentication.

tags | memory leak
systems | cisco
SHA-256 | f78e1da717f41cb8bc980acf491fc47ff430a1f0ad3b5d1aa403d9b8a3328338

cisco.00-12-06.memleak

Change Mirror Download
-----BEGIN PGP SIGNED MESSAGE-----

Cisco Catalyst Memory Leak Vulnerability

Revision 1.0
For Release 2000 December 6 08:00 AM US/Pacific (UTC+0700)

_________________________________________________________________

Summary

A series of failed telnet authentication attempts to the switch can cause
the Catalyst Switch to fail to pass traffic or accept management
connections until the system is rebooted or a power cycle is performed. All
types of telnet authentication are affected, including Kerberized telnet,
and AAA authentication.

This vulnerability has been assigned Cisco bug ID CSCds66191.

The complete advisory can be viewed at
http://www.cisco.com/warp/public/707/catalyst-memleak-pub.shtml.

Affected Products

Catalyst 4000 and 5000 images running version 4.5(2) up to 5.5(4) and
5.5(4a).
Catalyst 6000 images running version 5.3(1)CSX, up to and including 5.5(4),
5.5(4a).

No other releases of Cisco Catalyst software are affected by this
vulnerability.
No other Cisco products are affected by this vulnerability.

Details

The telnet process fails to release resources upon a failed authentication,
or a successful login of extremely short duration such as a telnet from
within an automated script. This memory leak eventually results in the
failure of the switch to perform any other processes, such as forwarding
traffic or management; a power cycle or reboot is required for recovery.

The command "show process memory" will indicate increased "Holding" memory
after failed telnet authentication attempts. This value will not decrease
over time except when a reboot, reload, or power cycle occurs. This bug may
be triggered over a period of time in the course of normal operation by
legitimate users that occasionally fail authentication.

lt-6509-e> (enable) sh proc mem

Memory Used: 3974544
Free: 15265168
Total: 19239712

PID TTY Allocated Freed Holding Process
- ---------- ---------- ---------- ---------- ---------- ---------------
1 -2 1707632 3488 1704144 Kernel and Idle

24 -2 16 0 16 telnetd

Impact

This vulnerability enables a Denial of Service attack on the Catalyst
switch.

Software Versions and Fixes

Cisco has made the following fixed software available to customers:

Catalyst Release 4.5(10) for Catalyst 4000 and 5000.
Catalyst Release 5.5(4b) for Catalyst 4000, 5000 and 6000.

The fix will be carried forward into all future releases.

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 through 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: tac@cisco.com

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 "psirt@cisco.com" or
"security-alert@cisco.com" for software upgrades.

Workarounds

There is no configuration workaround to eliminate the problem. However, if
you are unable to upgrade to an unaffected version, you may use other
devices to strictly control or prohibit telnet access to the switch,
permitting only connections from your local network.

Access control lists on the switch can limit the remote exploitation of the
vulnerability. To limit access to known hosts use the following commands:

set ip permit enable telnet
set ip permit <addr> [mask]

Remote management of the switch can also be disabled.

The above workarounds are provided as an option; however, the
recommendation is to upgrade to fixed code as soon as possible.

Exploitation and Public Announcements

Cisco Systems knows of no public discussion nor active exploits involving
this vulnerability, which was reported by a customer who noted the memory
leak.

Status of This Notice: FINAL

This is a final field 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/catalyst-memleak-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:

* cust-security-announce@cisco.com
* bugtraq@securityfocus.com
* first-teams@first.org (includes CERT/CC)
* cisco@spot.colorado.edu
* 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 1.006-DEC-2000 Initial public release.

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.

_________________________________________________________________

-----BEGIN PGP SIGNATURE-----
Version: PGP 6.0.2

iQEVAwUBOi5pUmiN3BRdFxkbAQE7jwf6A21IUrXrGI1ZueXwaBymh2xVDfnKee4R
KFybnDfNYTEAs5L5pE62x5QnL7xEQ+W5arZzmTKpxD9e+No7RUaSTVvUUJc5LIWn
zMCGfUdiwVKKtMSWqJR7GApmlnhY0f5sw8e/pMZKmcN1f5ZArNEZjoTca9nr4l67
XEvC3A2iUS+olT33YSsAogqt7gPVY6WNRKKvkw0xuxzXm6LKnlVCPGqMYP6fcMrr
7Dpb8mwl/abJT5tAZ/bbuKj+EKfzsw6E7mSIKfCf6n3Q0+rzlMhn3sWd/IvrXJII
Diw2o0HSvRkfMfIoVjchCYSU5Ph5BLF5bP9RpA6DwKTD3nRZEj3Cmw==
=Hs5N
-----END PGP SIGNATURE-----
Login or Register to add favorites

File Archive:

July 2024

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Jul 1st
    27 Files
  • 2
    Jul 2nd
    10 Files
  • 3
    Jul 3rd
    35 Files
  • 4
    Jul 4th
    27 Files
  • 5
    Jul 5th
    18 Files
  • 6
    Jul 6th
    0 Files
  • 7
    Jul 7th
    0 Files
  • 8
    Jul 8th
    28 Files
  • 9
    Jul 9th
    44 Files
  • 10
    Jul 10th
    24 Files
  • 11
    Jul 11th
    25 Files
  • 12
    Jul 12th
    11 Files
  • 13
    Jul 13th
    0 Files
  • 14
    Jul 14th
    0 Files
  • 15
    Jul 15th
    28 Files
  • 16
    Jul 16th
    6 Files
  • 17
    Jul 17th
    34 Files
  • 18
    Jul 18th
    6 Files
  • 19
    Jul 19th
    34 Files
  • 20
    Jul 20th
    0 Files
  • 21
    Jul 21st
    0 Files
  • 22
    Jul 22nd
    0 Files
  • 23
    Jul 23rd
    0 Files
  • 24
    Jul 24th
    0 Files
  • 25
    Jul 25th
    0 Files
  • 26
    Jul 26th
    0 Files
  • 27
    Jul 27th
    0 Files
  • 28
    Jul 28th
    0 Files
  • 29
    Jul 29th
    0 Files
  • 30
    Jul 30th
    0 Files
  • 31
    Jul 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2022 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close