NetKit-telnetd: buffer overflows in telnet and telnetd
Gentoo Linux Security Advisory
||GLSA 200410-03 / netkit-telnetd
||October 05, 2004
||October 05, 2004: 01
All supported architectures
Buffer overflows exist in the telnet client and daemon provided by
netkit-telnetd, which could possibly allow a remote attacker to gain root
privileges and compromise the system.
NetKit-telnetd is a standard Linux telnet client and server from the NetKit
A possible buffer overflow exists in the parsing of option strings by the
telnet daemon, where proper bounds checking is not applied when writing to
a buffer. Additionaly, another possible buffer overflow has been found by
Josh Martin in the handling of the environment variable HOME.
A remote attacker sending a specially-crafted options string to the telnet
daemon could be able to run arbitrary code with the privileges of the user
running the telnet daemon, usually root. Furthermore, an attacker could
make use of an overlong HOME variable to cause a buffer overflow in the
telnet client, potentially leading to the local execution of arbitrary
There is no known workaround at this time.
All NetKit-telnetd users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge sync
# emerge -pv ">=net-misc/netkit-telnetd-0.17-r4"
# emerge ">=net-misc/netkit-telnetd-0.17-r4"