USN-101-1: telnet vulnerabilities

Releases

• Ubuntu 4.10

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)

Update instructions

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

Ubuntu 4.10

• telnetd -
• telnet -

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

References

• CVE-2004-0911
• CVE-2005-0469

Related notices

• USN-224-1: krb5-rsh-server, kerberos4kth-clients, krb5-kdc, krb5-telnetd, krb5-clients