fail2ban/ca2b94c5229bd474f612b57b67d796252a4aab7a.patch

From ca2b94c5229bd474f612b57b67d796252a4aab7a Mon Sep 17 00:00:00 2001
From: sebres <serg.brester@sebres.de>
Date: Tue, 4 Oct 2022 14:03:07 +0200
Subject: [PATCH] fixes gh-3370: resolve extremely long search by repeated
 apply of non-greedy RE `(?:: (?:[^\(]+|\w+\([^\)]*\))+)?` with following
 branches (it may be extremely slow up to infinite search depending on
 message); added new regression tests amend to gh-3210: fixes regression and
 matches new format in aggressive mode too

---
 ChangeLog                         |  4 ++++
 config/filter.d/dovecot.conf      |  8 +++++---
 fail2ban/tests/files/logs/dovecot | 22 ++++++++++++++++++++++
 3 files changed, 31 insertions(+), 3 deletions(-)

Index: fail2ban-1.0.1/config/filter.d/dovecot.conf
===================================================================
--- fail2ban-1.0.1.orig/config/filter.d/dovecot.conf
+++ fail2ban-1.0.1/config/filter.d/dovecot.conf
@@ -7,19 +7,21 @@ before = common.conf
 
 [Definition]
 
+_daemon = (?:dovecot(?:-auth)?|auth)
+
 _auth_worker = (?:dovecot: )?auth(?:-worker)?
 _auth_worker_info = (?:conn \w+:auth(?:-worker)? \([^\)]+\): auth(?:-worker)?<\d+>: )?
-_daemon = (?:dovecot(?:-auth)?|auth)
+_bypass_reject_reason = (?:: (?:\w+\([^\):]*\) \w+|[^\(]+))*
 
 prefregex = ^%(__prefix_line)s(?:%(_auth_worker)s(?:\([^\)]+\))?: )?(?:%(__pam_auth)s(?:\(dovecot:auth\))?: |(?:pop3|imap|managesieve|submission)-login: )?(?:Info: )?%(_auth_worker_info)s<F-CONTENT>.+</F-CONTENT>$
 
 failregex = ^authentication failure; logname=<F-ALT_USER1>\S*</F-ALT_USER1> uid=\S* euid=\S* tty=dovecot ruser=<F-USER>\S*</F-USER> rhost=<HOST>(?:\s+user=<F-ALT_USER>\S*</F-ALT_USER>)?\s*$
-            ^(?:Aborted login|Disconnected|Remote closed connection|Client has quit the connection)(?:: (?:[^\(]+|\w+\([^\)]*\))+)? \((?:auth failed, \d+ attempts(?: in \d+ secs)?|tried to use (?:disabled|disallowed) \S+ auth|proxy dest auth failed)\):(?: user=<<F-USER>[^>]*</F-USER>>,)?(?: method=\S+,)? rip=<HOST>(?:[^>]*(?:, session=<\S+>)?)\s*$
+            ^(?:Aborted login|Disconnected|Remote closed connection|Client has quit the connection)%(_bypass_reject_reason)s \((?:auth failed, \d+ attempts(?: in \d+ secs)?|tried to use (?:disabled|disallowed) \S+ auth|proxy dest auth failed)\):(?: user=<<F-USER>[^>]*</F-USER>>,)?(?: method=\S+,)? rip=<HOST>(?:[^>]*(?:, session=<\S+>)?)\s*$
             ^pam\(\S+,<HOST>(?:,\S*)?\): pam_authenticate\(\) failed: (?:User not known to the underlying authentication module: \d+ Time\(s\)|Authentication failure \([Pp]assword mismatch\?\)|Permission denied)\s*$
             ^[a-z\-]{3,15}\(\S*,<HOST>(?:,\S*)?\): (?:[Uu]nknown user|[Ii]nvalid credentials|[Pp]assword mismatch)
             <mdre-<mode>>
 
-mdre-aggressive = ^(?:Aborted login|Disconnected|Remote closed connection|Client has quit the connection)(?::(?: [^ \(]+)+)? \((?:no auth attempts|disconnected before auth was ready,|client didn't finish \S+ auth,)(?: (?:in|waited) \d+ secs)?\):(?: user=<[^>]*>,)?(?: method=\S+,)? rip=<HOST>(?:[^>]*(?:, session=<\S+>)?)\s*$
+mdre-aggressive = ^(?:Aborted login|Disconnected|Remote closed connection|Client has quit the connection)%(_bypass_reject_reason)s \((?:no auth attempts|disconnected before auth was ready,|client didn't finish \S+ auth,)(?: (?:in|waited) \d+ secs)?\):(?: user=<[^>]*>,)?(?: method=\S+,)? rip=<HOST>(?:[^>]*(?:, session=<\S+>)?)\s*$
 
 mdre-normal = 
 
Index: fail2ban-1.0.1/fail2ban/tests/files/logs/dovecot
===================================================================
--- fail2ban-1.0.1.orig/fail2ban/tests/files/logs/dovecot
+++ fail2ban-1.0.1/fail2ban/tests/files/logs/dovecot
@@ -115,6 +115,17 @@ Aug 28 06:38:51 s166-62-100-187 dovecot:
 # failJSON: { "time": "2004-08-28T06:38:52", "match": true , "host": "192.0.2.4", "desc": "open parenthesis in optional part between Disconnected and (auth failed ...), gh-3210" }
 Aug 28 06:38:52 s166-62-100-187 dovecot: imap-login: Disconnected: Connection closed: read(size=1003) failed: Connection reset by peer (auth failed, 1 attempts in 0 secs): user=<test@example.com>, rip=192.0.2.4, lip=127.0.0.19, session=<Lsz0Oo7WXti3b7xe>
 
+# failJSON: { "time": "2004-08-29T01:49:33", "match": false , "desc": "avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: imap-login: Disconnected: Connection closed: read(size=1026) failed: Connection reset by peer (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1, TLS handshaking: read(size=1026) failed: Connection reset by peer
+# failJSON: { "time": "2004-08-29T01:49:33", "match": false , "desc": "avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: imap-login: Disconnected: Connection closed: SSL_accept() failed: error:1408F10B:SSL routines:ssl3_get_record:wrong version number (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1, TLS handshaking: SSL_accept() failed: error:1408F10B:SSL routines:ssl3_get_record:wrong version number
+# failJSON: { "time": "2004-08-29T01:49:33", "match": false , "desc": "avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: managesieve-login: Disconnected: Too many invalid commands. (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1
+# failJSON: { "time": "2004-08-29T01:49:33", "match": false , "desc": "avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: managesieve-login: Disconnected: Connection closed: read(size=1007) failed: Connection reset by peer (no auth attempts in 1 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1
+# failJSON: { "time": "2004-08-29T01:49:33", "match": false , "desc": "avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[472]: imap-login: Disconnected: Connection closed: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1, TLS handshaking: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol
+
 # failJSON: { "time": "2004-08-29T03:17:18", "match": true , "host": "192.0.2.133" }
 Aug 29 03:17:18 server dovecot: submission-login: Client has quit the connection (auth failed, 1 attempts in 2 secs): user=<user1>, method=LOGIN, rip=192.0.2.133, lip=0.0.0.0
 # failJSON: { "time": "2004-08-29T03:53:52", "match": true , "host": "192.0.2.169" }
@@ -128,6 +139,17 @@ Aug 29 15:33:53 server dovecot: managesi
 
 # filterOptions: [{"mode": "aggressive"}]
 
+# failJSON: { "time": "2004-08-29T01:49:33", "match": true , "host": "192.0.2.5", "desc": "matches in aggressive mode, avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: imap-login: Disconnected: Connection closed: read(size=1026) failed: Connection reset by peer (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1, TLS handshaking: read(size=1026) failed: Connection reset by peer
+# failJSON: { "time": "2004-08-29T01:49:33", "match": true , "host": "192.0.2.5", "desc": "matches in aggressive mode, avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: imap-login: Disconnected: Connection closed: SSL_accept() failed: error:1408F10B:SSL routines:ssl3_get_record:wrong version number (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1, TLS handshaking: SSL_accept() failed: error:1408F10B:SSL routines:ssl3_get_record:wrong version number
+# failJSON: { "time": "2004-08-29T01:49:33", "match": true , "host": "192.0.2.5", "desc": "matches in aggressive mode, avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: managesieve-login: Disconnected: Too many invalid commands. (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1
+# failJSON: { "time": "2004-08-29T01:49:33", "match": true , "host": "192.0.2.5", "desc": "matches in aggressive mode, avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[459]: managesieve-login: Disconnected: Connection closed: read(size=1007) failed: Connection reset by peer (no auth attempts in 1 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1
+# failJSON: { "time": "2004-08-29T01:49:33", "match": true , "host": "192.0.2.5", "desc": "matches in aggressive mode, avoid slow RE, gh-3370" }
+Aug 29 01:49:33 server dovecot[472]: imap-login: Disconnected: Connection closed: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol (no auth attempts in 0 secs): user=<>, rip=192.0.2.5, lip=127.0.0.1, TLS handshaking: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol
+
 # failJSON: { "time": "2004-08-29T16:06:58", "match": true , "host": "192.0.2.5" }
 Aug 29 16:06:58 s166-62-100-187 dovecot: imap-login: Disconnected (disconnected before auth was ready, waited 0 secs): user=<>, rip=192.0.2.5, lip=192.168.1.2, TLS handshaking: SSL_accept() syscall failed: Connection reset by peer
 # failJSON: { "time": "2004-08-31T16:15:10", "match": true , "host": "192.0.2.6" }