[<prev] [next>] [day] [month] [year] [list]
Date: Tue, 7 Feb 2023 10:49:47 -0800
From: David Leadbeater <dgl@....cx>
To: oss-security@...ts.openwall.com
Subject: CVE-2022-46663: less -R filtering bypass
Hi,
I discovered a way to bypass the escape sequence filtering performed
by less -R due to incorrect terminal state machine handling.
The fix is:
https://github.com/gwsw/less/commit/a78e1351113cef564d790a730d657a321624d79c
but not yet part of any less release.
An example that results in a DoS in xterm or iTerm 2 is:
printf "\e]8;;\e0m\e[>0q" > less-example-xtversion
less -R less-example-xtversion
This has the result of getting the terminal to reply with something
like "\eP>|name version". The "P" there makes less scroll up, the ">"
makes it scroll down, and then it prints the same thing to the tty,
rinse, repeat.
This affects GNU less >= 566 (and <609, but version 608 is the last
public release, the later version numbers are snapshots).
David
Powered by blists - more mailing lists
Please check out the
Open Source Software Security Wiki, which is counterpart to this
mailing list.
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
