English | Deutsch | Español | Português
 UserID:
 Passwd:
new user
 About:   Dedicated  | Advanced  | Standard  | Recurring  | No Risk  | Desktop  | Basic  | Single  | Security Seal  | FAQ
  Price/Feature Summary  | Order  | New Vulnerabilities  | Confidentiality  | Vulnerability Search
 Vulnerability   
Search   
    Search 143769 CVE descriptions
and 71225 test descriptions,
access 10,000+ cross references.
Tests   CVE   All  

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

=============================================================================
FreeBSD-SA-05:01.telnet                                     Security Advisory
                                                          The FreeBSD Project

Topic:          telnet client buffer overflows

Category:       contrib
Module:         contrib/telnet
Announced:      2005-03-28
Credits:        iDEFENSE
Affects:        All FreeBSD releases prior to 5.4-RELEASE
Corrected:      2005-03-28 15:50:00 UTC (RELENG_5, 5.4-PRERELEASE)
                2005-03-28 15:48:00 UTC (RELENG_4, 4.11-STABLE)
                2005-03-28 15:52:00 UTC (RELENG_5_3, 5.3-RELEASE-p6)
                2005-03-28 15:57:00 UTC (RELENG_4_11, 4.11-RELEASE-p1)
                2005-03-28 15:58:00 UTC (RELENG_4_10, 4.10-RELEASE-p6)
                2005-03-28 16:00:00 UTC (RELENG_4_8, 4.8-RELEASE-p28)
CVE Name:       CAN-2005-0468 CAN-2005-0469

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit
<URL:http://www.freebsd.org/security/>.

I.   Background

The telnet(1) command is a TELNET protocol client, used primarily to
establish terminal sessions across a network.

II.  Problem Description

Buffer overflows were discovered in the env_opt_add() and
slc_add_reply() functions of the telnet(1) command.  TELNET protocol
commands, options, and data are copied from the network to a
fixed-sized buffer.  In the case of env_opt_add (CAN-2005-0468), the
buffer is located on the heap.  In the case of slc_add_reply
(CAN-2005-0469), the buffer is global uninitialized data (BSS).

III. Impact

These buffer overflows may be triggered when connecting to a malicious
server, or by an active attacker in the network path between the
client and server.  Specially crafted TELNET command sequences may
cause the execution of arbitrary code with the privileges of the user
invoking telnet(1).

IV.  Workaround

Do not use telnet(1) to connect to untrusted machines or over an
untrusted network.

V.   Solution

Perform one of the following:

1) Upgrade your vulnerable system to 4-STABLE or 5-STABLE, or to the
RELENG_5_3, RELENG_4_11, RELENG_4_10, or RELENG_4_8 security branch
dated after the correction date.

2) To patch your present system:

The following patches have been verified to apply to FreeBSD 4.8, 4.10,
4.11, and 5.3 systems.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

[FreeBSD 4.x]
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:01/telnet4.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:01/telnet4.patch.asc

[FreeBSD 5.x]
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:01/telnet5.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-05:01/telnet5.patch.asc

b) Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch

c) Rebuild the operating system as described in
<URL:http://www.freebsd.org/doc/handbook/makeworld.html>.

VI.  Correction details

The following list contains the revision numbers of each file that was
corrected in FreeBSD.

Branch                                                           Revision
  Path
- -------------------------------------------------------------------------
RELENG_4
  src/crypto/heimdal/appl/telnet/telnet/telnet.c              1.1.1.1.2.4
  src/crypto/kerberosIV/appl/telnet/telnet/telnet.c           1.1.1.1.2.1
  src/crypto/telnet/telnet/telnet.c                               1.4.2.6
  src/usr.bin/telnet/telnet.c                                     1.8.2.4
RELENG_4_11
  src/UPDATING                                              1.73.2.91.2.2
  src/crypto/heimdal/appl/telnet/telnet/telnet.c         1.1.1.1.2.3.10.1
  src/crypto/kerberosIV/appl/telnet/telnet/telnet.c          1.1.1.1.22.1
  src/crypto/telnet/telnet/telnet.c                          1.4.2.5.12.1
  src/sys/conf/newvers.sh                                   1.44.2.39.2.5
  src/usr.bin/telnet/telnet.c                                1.8.2.3.12.1
RELENG_4_10
  src/UPDATING                                              1.73.2.90.2.7
  src/crypto/heimdal/appl/telnet/telnet/telnet.c          1.1.1.1.2.3.8.1
  src/crypto/kerberosIV/appl/telnet/telnet/telnet.c          1.1.1.1.20.1
  src/crypto/telnet/telnet/telnet.c                          1.4.2.5.10.1
  src/sys/conf/newvers.sh                                   1.44.2.34.2.8
  src/usr.bin/telnet/telnet.c                                1.8.2.3.10.1
RELENG_4_8
  src/UPDATING                                             1.73.2.80.2.32
  src/crypto/heimdal/appl/telnet/telnet/telnet.c          1.1.1.1.2.3.4.1
  src/crypto/kerberosIV/appl/telnet/telnet/telnet.c          1.1.1.1.16.1
  src/crypto/telnet/telnet/telnet.c                           1.4.2.5.6.1
  src/sys/conf/newvers.sh                                  1.44.2.29.2.29
  src/usr.bin/telnet/telnet.c                                 1.8.2.3.6.1
RELENG_5
  src/contrib/telnet/telnet/telnet.c                             1.14.6.1
RELENG_5_3
  src/UPDATING                                             1.342.2.13.2.9
  src/contrib/telnet/telnet/telnet.c                             1.14.8.1
  src/sys/conf/newvers.sh                                  1.62.2.15.2.11
- -------------------------------------------------------------------------

VII. References

[IDEF0866] Multiple Telnet Client slc_add_reply() Buffer Overflow
http://www.idefense.com/application/poi/display?id=220&type=vulnerabilities

[IDEF0867] Multiple Telnet Client env_opt_add() Buffer Overflow
http://www.idefense.com/application/poi/display?id=221&type=vulnerabilities
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.0

iD8DBQFCSECrFdaIBMps37IRAnRJAJ0VbP6TyaX7SLE2EwSrIYU25JSD9wCfYoe9
Qg2Lw/6QFLOgYG1jPuzogEs=
=0rFv
-----END PGP SIGNATURE-----

New User Registration
Email:
UserID:
Passwd:
Please email me your monthly newsletters, informing the latest services, improvements & surveys.
Please email me a vulnerability test announcement whenever a new test is added.
   Privacy
Registered User Login
 
UserID:   
Passwd:  

 Forgot userid or passwd?
Email/Userid:




Home | About Us | Contact Us | Partner Programs | Developer APIs | Privacy | Mailing Lists | Abuse
Security Audits | Managed DNS | Network Monitoring | Site Analyzer | Internet Research Reports
Web Probe

© 1998-2019 E-Soft Inc. All rights reserved.