Skip to content

Commit

Permalink
fixed possible RCE vulnerability, unset escape variable (default tild…
Browse files Browse the repository at this point in the history
…e) stops consider "~" char after new-line as composing escape sequence
  • Loading branch information
sebres committed Jun 21, 2021
1 parent 92f9003 commit 410a6ce
Show file tree
Hide file tree
Showing 6 changed files with 13 additions and 13 deletions.
2 changes: 1 addition & 1 deletion config/action.d/complain.conf
Expand Up @@ -102,7 +102,7 @@ logpath = /dev/null
# Notes.: Your system mail command. Is passed 2 args: subject and recipient
# Values: CMD
#
mailcmd = mail -s
mailcmd = mail -E 'set escape' -s

# Option: mailargs
# Notes.: Additional arguments to mail command. e.g. for standard Unix mail:
Expand Down
2 changes: 1 addition & 1 deletion config/action.d/dshield.conf
Expand Up @@ -179,7 +179,7 @@ tcpflags =
# Notes.: Your system mail command. Is passed 2 args: subject and recipient
# Values: CMD
#
mailcmd = mail -s
mailcmd = mail -E 'set escape' -s

# Option: mailargs
# Notes.: Additional arguments to mail command. e.g. for standard Unix mail:
Expand Down
8 changes: 4 additions & 4 deletions config/action.d/mail-buffered.conf
Expand Up @@ -17,7 +17,7 @@ actionstart = printf %%b "Hi,\n
The jail <name> has been started successfully.\n
Output will be buffered until <lines> lines are available.\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: started on <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: started on <fq-hostname>" <dest>

# Option: actionstop
# Notes.: command executed at the stop of jail (or at the end of Fail2Ban)
Expand All @@ -28,13 +28,13 @@ actionstop = if [ -f <tmpfile> ]; then
These hosts have been banned by Fail2Ban.\n
`cat <tmpfile>`
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: Summary from <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: Summary from <fq-hostname>" <dest>
rm <tmpfile>
fi
printf %%b "Hi,\n
The jail <name> has been stopped.\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: stopped on <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: stopped on <fq-hostname>" <dest>

# Option: actioncheck
# Notes.: command executed once before each actionban command
Expand All @@ -55,7 +55,7 @@ actionban = printf %%b "`date`: <ip> (<failures> failures)\n" >> <tmpfile>
These hosts have been banned by Fail2Ban.\n
`cat <tmpfile>`
\nRegards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: Summary" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: Summary" <dest>
rm <tmpfile>
fi

Expand Down
2 changes: 1 addition & 1 deletion config/action.d/mail-whois-lines.conf
Expand Up @@ -72,7 +72,7 @@ actionunban =
# Notes.: Your system mail command. Is passed 2 args: subject and recipient
# Values: CMD
#
mailcmd = mail -s
mailcmd = mail -E 'set escape' -s

# Default name of the chain
#
Expand Down
6 changes: 3 additions & 3 deletions config/action.d/mail-whois.conf
Expand Up @@ -20,7 +20,7 @@ norestored = 1
actionstart = printf %%b "Hi,\n
The jail <name> has been started successfully.\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: started on <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: started on <fq-hostname>" <dest>

# Option: actionstop
# Notes.: command executed at the stop of jail (or at the end of Fail2Ban)
Expand All @@ -29,7 +29,7 @@ actionstart = printf %%b "Hi,\n
actionstop = printf %%b "Hi,\n
The jail <name> has been stopped.\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: stopped on <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: stopped on <fq-hostname>" <dest>

# Option: actioncheck
# Notes.: command executed once before each actionban command
Expand All @@ -49,7 +49,7 @@ actionban = printf %%b "Hi,\n
Here is more information about <ip> :\n
`%(_whois_command)s`\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: banned <ip> from <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: banned <ip> from <fq-hostname>" <dest>

# Option: actionunban
# Notes.: command executed when unbanning an IP. Take care that the
Expand Down
6 changes: 3 additions & 3 deletions config/action.d/mail.conf
Expand Up @@ -16,7 +16,7 @@ norestored = 1
actionstart = printf %%b "Hi,\n
The jail <name> has been started successfully.\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: started on <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: started on <fq-hostname>" <dest>

# Option: actionstop
# Notes.: command executed at the stop of jail (or at the end of Fail2Ban)
Expand All @@ -25,7 +25,7 @@ actionstart = printf %%b "Hi,\n
actionstop = printf %%b "Hi,\n
The jail <name> has been stopped.\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: stopped on <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: stopped on <fq-hostname>" <dest>

# Option: actioncheck
# Notes.: command executed once before each actionban command
Expand All @@ -43,7 +43,7 @@ actionban = printf %%b "Hi,\n
The IP <ip> has just been banned by Fail2Ban after
<failures> attempts against <name>.\n
Regards,\n
Fail2Ban"|mail -s "[Fail2Ban] <name>: banned <ip> from <fq-hostname>" <dest>
Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] <name>: banned <ip> from <fq-hostname>" <dest>

# Option: actionunban
# Notes.: command executed when unbanning an IP. Take care that the
Expand Down

1 comment on commit 410a6ce

@dorchain
Copy link

@dorchain dorchain commented on 410a6ce Jul 23, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

see #3059

Please sign in to comment.