From 410a6ce5c80dd981c22752da034f2529b5eee844 Mon Sep 17 00:00:00 2001 From: sebres Date: Mon, 21 Jun 2021 17:12:53 +0200 Subject: [PATCH] fixed possible RCE vulnerability, unset escape variable (default tilde) stops consider "~" char after new-line as composing escape sequence [Retrieved from: https://github.com/fail2ban/fail2ban/commit/410a6ce5c80dd981c22752da034f2529b5eee844] Signed-off-by: Fabrice Fontaine --- config/action.d/complain.conf | 2 +- config/action.d/dshield.conf | 2 +- config/action.d/mail-buffered.conf | 8 ++++---- config/action.d/mail-whois-lines.conf | 2 +- config/action.d/mail-whois.conf | 6 +++--- config/action.d/mail.conf | 6 +++--- 6 files changed, 13 insertions(+), 13 deletions(-) diff --git a/config/action.d/complain.conf b/config/action.d/complain.conf index 3a5f882c9f..4d73b05859 100644 --- a/config/action.d/complain.conf +++ b/config/action.d/complain.conf @@ -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: diff --git a/config/action.d/dshield.conf b/config/action.d/dshield.conf index c128bef348..3d5a7a53a9 100644 --- a/config/action.d/dshield.conf +++ b/config/action.d/dshield.conf @@ -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: diff --git a/config/action.d/mail-buffered.conf b/config/action.d/mail-buffered.conf index 325f185b2f..79b841049c 100644 --- a/config/action.d/mail-buffered.conf +++ b/config/action.d/mail-buffered.conf @@ -17,7 +17,7 @@ actionstart = printf %%b "Hi,\n The jail has been started successfully.\n Output will be buffered until lines are available.\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : started on " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : started on " # Option: actionstop # Notes.: command executed at the stop of jail (or at the end of Fail2Ban) @@ -28,13 +28,13 @@ actionstop = if [ -f ]; then These hosts have been banned by Fail2Ban.\n `cat ` Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : Summary from " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : Summary from " rm fi printf %%b "Hi,\n The jail has been stopped.\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : stopped on " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : stopped on " # Option: actioncheck # Notes.: command executed once before each actionban command @@ -55,7 +55,7 @@ actionban = printf %%b "`date`: ( failures)\n" >> These hosts have been banned by Fail2Ban.\n `cat ` \nRegards,\n - Fail2Ban"|mail -s "[Fail2Ban] : Summary" + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : Summary" rm fi diff --git a/config/action.d/mail-whois-lines.conf b/config/action.d/mail-whois-lines.conf index 3a3e56b2c7..d2818cb9b9 100644 --- a/config/action.d/mail-whois-lines.conf +++ b/config/action.d/mail-whois-lines.conf @@ -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 # diff --git a/config/action.d/mail-whois.conf b/config/action.d/mail-whois.conf index 7fea34c40d..ab33b616dc 100644 --- a/config/action.d/mail-whois.conf +++ b/config/action.d/mail-whois.conf @@ -20,7 +20,7 @@ norestored = 1 actionstart = printf %%b "Hi,\n The jail has been started successfully.\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : started on " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : started on " # Option: actionstop # Notes.: command executed at the stop of jail (or at the end of Fail2Ban) @@ -29,7 +29,7 @@ actionstart = printf %%b "Hi,\n actionstop = printf %%b "Hi,\n The jail has been stopped.\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : stopped on " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : stopped on " # Option: actioncheck # Notes.: command executed once before each actionban command @@ -49,7 +49,7 @@ actionban = printf %%b "Hi,\n Here is more information about :\n `%(_whois_command)s`\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : banned from " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : banned from " # Option: actionunban # Notes.: command executed when unbanning an IP. Take care that the diff --git a/config/action.d/mail.conf b/config/action.d/mail.conf index 5d8c0e154c..f4838ddcb6 100644 --- a/config/action.d/mail.conf +++ b/config/action.d/mail.conf @@ -16,7 +16,7 @@ norestored = 1 actionstart = printf %%b "Hi,\n The jail has been started successfully.\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : started on " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : started on " # Option: actionstop # Notes.: command executed at the stop of jail (or at the end of Fail2Ban) @@ -25,7 +25,7 @@ actionstart = printf %%b "Hi,\n actionstop = printf %%b "Hi,\n The jail has been stopped.\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : stopped on " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : stopped on " # Option: actioncheck # Notes.: command executed once before each actionban command @@ -43,7 +43,7 @@ actionban = printf %%b "Hi,\n The IP has just been banned by Fail2Ban after attempts against .\n Regards,\n - Fail2Ban"|mail -s "[Fail2Ban] : banned from " + Fail2Ban"|mail -E 'set escape' -s "[Fail2Ban] : banned from " # Option: actionunban # Notes.: command executed when unbanning an IP. Take care that the