The telnet-bsd telnet client is vulnerable to two buffer overflows, which could allow a malicious telnet server operator to execute arbitrary code.
| Package | Arch | Vulnerable | Unaffected |
|---|---|---|---|
| net-misc/telnet-bsd | * | < 1.0-r1 | >= 1.0-r1 |
telnet-bsd provides a command line telnet client which is used for remote login using the telnet protocol.
A buffer overflow has been identified in the env_opt_add() function of telnet-bsd, where a response requiring excessive escaping can cause a heap-based buffer overflow. Another issue has been identified in the slc_add_reply() function, where a large number of SLC commands can overflow a fixed size buffer.
Successful exploitation would require a vulnerable user to connect to an attacker-controlled host using telnet, potentially executing arbitrary code with the permissions of the telnet user.
There is no known workaround at this time.
All telnet-bsd users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=net-misc/telnet-bsd-1.0-r1"