diff --git a/ChangeLog b/ChangeLog index 2a6b5733..1ed40dca 100644 --- a/ChangeLog +++ b/ChangeLog @@ -38,6 +38,10 @@ releases. - Optional reason part in message after FAIL LOGIN (gh-1543) * `filter.d/sendmail-reject.conf` - removed mandatory double space (if dns-host available, gh-1579) +* filter.d/sshd.conf + - recognized "Failed publickey for" (gh-1477); + - optimized failregex to match all of "Failed any-method for ... from " (gh-1479) + - eliminated possible complex injections (on user-name resp. auth-info, see gh-1479) ### New Features diff --git a/config/filter.d/sshd.conf b/config/filter.d/sshd.conf index eeb1518e..9a3d40f0 100644 --- a/config/filter.d/sshd.conf +++ b/config/filter.d/sshd.conf @@ -20,7 +20,7 @@ _daemon = sshd failregex = ^%(__prefix_line)s(?:error: PAM: )?[aA]uthentication (?:failure|error|failed) for .* from ( via \S+)?\s*$ ^%(__prefix_line)s(?:error: PAM: )?User not known to the underlying authentication module for .* from \s*$ - ^%(__prefix_line)sFailed \S+ for .*? from (?: port \d*)?(?: ssh\d*)?(: (ruser .*|(\S+ ID \S+ \(serial \d+\) CA )?\S+ %(__md5hex)s(, client user ".*", client host ".*")?))?\s*$ + ^%(__prefix_line)sFailed \S+ for (?Pinvalid user )?(?P(?P\S+)|(?(cond_inv)(?:(?! from ).)*?|[^:]+)) from (?: port \d+)?(?: ssh\d*)?(?(cond_user):|(?:(?:(?! from ).)*)$) ^%(__prefix_line)sROOT LOGIN REFUSED.* FROM \s*$ ^%(__prefix_line)s[iI](?:llegal|nvalid) user .* from \s*$ ^%(__prefix_line)sUser .+ from not allowed because not listed in AllowUsers\s*$ diff --git a/fail2ban/tests/files/logs/sshd b/fail2ban/tests/files/logs/sshd index 7baf4be7..c53bbadb 100644 --- a/fail2ban/tests/files/logs/sshd +++ b/fail2ban/tests/files/logs/sshd @@ -117,7 +117,13 @@ Sep 29 17:15:02 spaceman sshd[12946]: Failed password for user from 127.0.0.1 po # failJSON: { "time": "2004-11-11T08:04:51", "match": true , "host": "127.0.0.1", "desc": "Injecting on username ssh 'from 10.10.1.1'@localhost" } Nov 11 08:04:51 redbamboo sshd[2737]: Failed password for invalid user from 10.10.1.1 from 127.0.0.1 port 58946 ssh2 +# failJSON: { "time": "2004-11-11T08:04:52", "match": true , "host": "127.0.0.1", "desc": "More complex injecting on username ssh 'test from 10.10.1.2 port 55555 ssh2'@localhost" } +Nov 11 08:04:52 redbamboo sshd[2737]: Failed password for invalid user test from 10.10.1.2 port 55555 ssh2 from 127.0.0.1 port 58946 ssh2 +# failJSON: { "time": "2004-11-11T08:04:52", "match": true , "host": "127.0.0.1", "desc": "More complex injecting on auth-info ssh test@localhost, auth-info: ' from 10.10.1.2 port 55555 ssh2'" } +Nov 11 08:04:52 redbamboo sshd[2737]: Failed password for invalid user test from 127.0.0.1 port 58946 ssh2: from 10.10.1.2 port 55555 ssh2 +# failJSON: { "time": "2005-07-05T18:22:44", "match": true , "host": "127.0.0.1", "desc": "Failed publickey for ..." } +Jul 05 18:22:44 mercury sshd[4669]: Failed publickey for graysky from 127.0.0.1 port 37954 ssh2: RSA SHA256:v3dpapGleDaUKf$4V1vKyR9ZyUgjaJAmoCTcb2PLljI # failJSON: { "match": false } Nov 23 21:50:19 sshd[8148]: Disconnecting: Too many authentication failures for root [preauth] @@ -161,4 +167,3 @@ Apr 27 13:02:04 host sshd[29116]: Received disconnect from 1.2.3.4: 11: Normal S # Match sshd auth errors on OpenSUSE systems # failJSON: { "time": "2015-04-16T20:02:50", "match": true , "host": "222.186.21.217", "desc": "Authentication for user failed" } 2015-04-16T18:02:50.321974+00:00 host sshd[2716]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=222.186.21.217 user=root -