1. Ubuntu Security Notices
  2. USN-101-1

USN-101-1: telnet vulnerabilities

Publication date

29 March 2005

Overview

telnet vulnerabilities

Releases

Details

A buffer overflow was discovered in the telnet client’s handling of
the LINEMODE suboptions. By sending a specially constructed reply
containing a large number of SLC (Set Local Character) commands, a
remote attacker (i. e. a malicious telnet server) could execute
arbitrary commands with the privileges of the user running the telnet
client. (CAN-2005-0469)

Michal Zalewski discovered a Denial of Service vulnerability in the
telnet server (telnetd). A remote attacker could cause the telnetd
process to free an invalid pointer, which caused the server process to
crash, leading to a denial of service (inetd will disable the service
if telnetd crashed repeatedly), or possibly the execution of arbitrary
code with the privileges of the telnetd process (by default,
the ‘telnetd’ user). Please note that the telnet server is not
officially supported by Ubuntu, it is in the “universe”
component. (CAN-2004-0911)

A buffer overflow was discovered in the telnet client’s handling of
the LINEMODE suboptions. By sending a specially constructed reply
containing a large number of SLC (Set Local Character) commands, a
remote attacker (i. e. a malicious telnet server) could execute
arbitrary commands with the privileges of the user running the telnet
client. (CAN-2005-0469)

Michal Zalewski discovered a Denial of Service vulnerability in the
telnet server (telnetd). A remote attacker could cause the telnetd
process to free an invalid pointer, which caused the server process to
crash, leading to a denial of service (inetd will disable the service
if telnetd crashed repeatedly), or possibly the execution of arbitrary
code with the privileges of the telnetd process (by default,
the ‘telnetd’ user). Please note that the telnet server is not
officially supported by Ubuntu, it is in the “universe”
component. (CAN-2004-0911)

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
4.10 warty telnetd – 
telnet – 

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References

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