From 8ee3a135527707f60baa948e35b78187787bc9f7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Peter=20M=C3=BCller?= Date: Mon, 29 Jul 2019 20:00:00 +0000 Subject: [PATCH] firewall: raise log rate limit to 10 packets per second MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Previous setting was to log 10 packets per minute for each event logging is turned on. This made debugging much harder, as the limit was rather strict and chances of dropping a packet without logging it were good. This patch changes the log rate limit to 10 packets per second per event, to avoid DoS attacks against the log file. I plan to drop log rate limit entirely in future changes, if a better solution for this attack vector is available. Signed-off-by: Peter Müller Cc: Tim FitzGeorge Cc: Michael Tremer Signed-off-by: Arne Fitzenreiter --- src/initscripts/system/firewall | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/src/initscripts/system/firewall b/src/initscripts/system/firewall index b3483a7440..ec396c708c 100644 --- a/src/initscripts/system/firewall +++ b/src/initscripts/system/firewall @@ -34,20 +34,20 @@ iptables_init() { # Empty LOG_DROP and LOG_REJECT chains iptables -N LOG_DROP - iptables -A LOG_DROP -m limit --limit 10/minute -j LOG + iptables -A LOG_DROP -m limit --limit 10/second -j LOG iptables -A LOG_DROP -j DROP iptables -N LOG_REJECT - iptables -A LOG_REJECT -m limit --limit 10/minute -j LOG + iptables -A LOG_REJECT -m limit --limit 10/second -j LOG iptables -A LOG_REJECT -j REJECT # This chain will log, then DROPs packets with certain bad combinations # of flags might indicate a port-scan attempt (xmas, null, etc) iptables -N PSCAN if [ "$DROPPORTSCAN" == "on" ]; then - iptables -A PSCAN -p tcp -m limit --limit 10/minute -j LOG --log-prefix "DROP_TCP Scan " -m comment --comment "DROP_TCP PScan" - iptables -A PSCAN -p udp -m limit --limit 10/minute -j LOG --log-prefix "DROP_UDP Scan " -m comment --comment "DROP_UDP PScan" - iptables -A PSCAN -p icmp -m limit --limit 10/minute -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan" - iptables -A PSCAN -f -m limit --limit 10/minute -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan" + iptables -A PSCAN -p tcp -m limit --limit 10/second -j LOG --log-prefix "DROP_TCP Scan " -m comment --comment "DROP_TCP PScan" + iptables -A PSCAN -p udp -m limit --limit 10/second -j LOG --log-prefix "DROP_UDP Scan " -m comment --comment "DROP_UDP PScan" + iptables -A PSCAN -p icmp -m limit --limit 10/second -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan" + iptables -A PSCAN -f -m limit --limit 10/second -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan" fi iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan" @@ -55,7 +55,7 @@ iptables_init() { # that's not covered above, may just be a broken windows machine iptables -N NEWNOTSYN if [ "$DROPNEWNOTSYN" == "on" ]; then - iptables -A NEWNOTSYN -m limit --limit 10/minute -j LOG --log-prefix "DROP_NEWNOTSYN " + iptables -A NEWNOTSYN -m limit --limit 10/second -j LOG --log-prefix "DROP_NEWNOTSYN " fi iptables -A NEWNOTSYN -j DROP -m comment --comment "DROP_NEWNOTSYN" -- 2.39.5