Bug 194934 - telnet(1) core dumped
Summary: telnet(1) core dumped
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: bin (show other bugs)
Version: 9.3-RELEASE
Hardware: amd64 Any
: --- Affects Only Me
Assignee: freebsd-bugs mailing list
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-11-10 21:36 UTC by Yves-Noel Weweler
Modified: 2017-05-26 11:54 UTC (History)
2 users (show)

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Description Yves-Noel Weweler 2014-11-10 21:36:17 UTC
Using the default "telnet" command from the FreeBSD 9.3-RELEASE

9.3-RELEASE FreeBSD 9.3-RELEASE #0 r268512: Thu Jul 10 23:44:39 UTC 2014

i am able to produce a core dump if pressing the key-combination STRG+5, STRG+4
after a plain connection to IPv4 based endpoint.


Example 1:
---------------------------------------
% telnet localhost 7777

Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
^]
telnet> ^\Verlassen(core dumped)



Core dumping telnet is even possible when pressing STRG+5 followed by any key combination closed by STRG+4.

Example 2:
---------------------------------------
% telnet localhost 7777
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
^]
telnet> 123456^\Verlassen(core dumped)
Comment 1 Koen Martens 2017-05-26 11:26:13 UTC
STRG = CTRL on non-german keyboards. It also core-dumps with this combination in 10.3 and 11.0. Also does this with the sequence ^[, ^\ .
Comment 2 Koen Martens 2017-05-26 11:54:47 UTC
Note that ^5 or ^\ sends a SIGQUIT, which by default means 'terminate and dump core'. So this is not a bug, rather it is expected behaviour.