RHSA-2005:327 - Security Advisory

Topic

Updated telnet packages that fix two buffer overflow vulnerabilities are
now available.

This update has been rated as having important security impact by the Red
Hat Security Response Team.

Description

The telnet package provides a command line telnet client. The telnet-server
package includes a telnet daemon, telnetd, that supports remote login to
the host machine.

Two buffer overflow flaws were discovered in the way the telnet client
handles messages from a server. An attacker may be able to execute
arbitrary code on a victim's machine if the victim can be tricked into
connecting to a malicious telnet server. The Common Vulnerabilities and
Exposures project (cve.mitre.org) has assigned the names CAN-2005-0468
and CAN-2005-0469 to these issues.

Additionally, the following bugs have been fixed in these erratum packages
for Red Hat Enterprise Linux 2.1 and Red Hat Enterprise Linux 3:

• telnetd could loop on an error in the child side process
• There was a race condition in telnetd on a wtmp lock on some occasions
• The command line in the process table was sometimes too long and caused

bad output from the ps command

• The 8-bit binary option was not working

Users of telnet should upgrade to this updated package, which contains
backported patches to correct these issues.

Red Hat would like to thank iDEFENSE for their responsible disclosure of
this issue.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied. Use Red Hat
Network to download and update your packages. To launch the Red Hat
Update Agent, use the following command:

up2date

For information on how to install packages manually, refer to the
following Web page for the System Administration or Customization
guide specific to your system:

http://www.redhat.com/docs/manuals/enterprise/

Affected Products

• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux Server 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Server 2 ia64
• Red Hat Enterprise Linux Server 2 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Workstation 2 ia64
• Red Hat Enterprise Linux Workstation 2 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 4 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 4 ppc
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 126858 - Too long /proc/X/cmdline: bad ps output when piped to less/more
• BZ - 145004 - telnetd cleanup() race condition with syslog in signal handler
• BZ - 145636 - [PATCH] telnetd loops on child IO error
• BZ - 147003 - [RHEL3] telnetd cleanup() race condition with syslog in signal handler
• BZ - 151297 - CAN-2005-0469 slc_add_reply() Buffer Overflow Vulnerability
• BZ - 151301 - CAN-2005-0468 env_opt_add() Buffer Overflow Vulnerability

CVEs

• CVE-2005-0469
• CVE-2005-0468

References

• http://www.idefense.com/application/poi/display?id=220&type=vulnerabilities
• http://www.idefense.com/application/poi/display?id=221&type=vulnerabilities