similar to: Repeated attacks via SSH

I was looking at my maillog and it looks like someone is trying to get into my pop3 server. Dec 9 15:28:54 mailserver dovecot: pop3-login: Aborted login: user=<alexis>, method=PLAIN, rip=::ffff:66.167.184.203, lip=::ffff:192.168.1.2 Dec 9 15:29:08 mailserver dovecot: pop3-login: Aborted login: user=<alfonso>, method=PLAIN, rip=::ffff:66.167.184.203, lip=::ffff:192.168.1.2 Dec 9

Gang, For months now, we're all seeing repeated bruteforce attempts on SSH. I've configured my pf install to ratelimit TCP connections to port 22 and to automatically add IP-addresses that connect too fast to a table that's filtered: table <lamers> { } block quick from <lamers> to any pass in quick on $ext_if inet proto tcp from any to ($ext_if) port 22 modulate

Good Day! I think we have a serious problem. One of our old server running FreeBSD 4.9 have been compromised and is now connected to an ircd server.. 195.204.1.132.6667 ESTABLISHED However, we still haven't brought the server down in an attempt to track the intruder down. Right now we are clueless as to what we need to do.. Most of our servers are running legacy operating systems(old

On Fri, 12 Apr 2019, mj wrote: > What we do is: use https://github.com/trick77/ipset-blacklist to block IPs > (from various existing blacklists) at the iptables level using an ipset. "www.blocklist.de" is a nifty source. Could you suggest other publically available blacklists? > That way, the known bad IPs never even talk to dovecot, but are dropped > immediately. We

Hello, What is the best way to protect multiuser systems from brute force attacks? I am setting up a relatively loose DenyHosts policy, but I like the idea of locking an account for a time if too many attempts are made, but to balance this with keeping the user from making a helpdesk call. What are some policies/techniques that have worked for this list with minimal hassle? Thanks! -Eugene

There is a lot of talk about the vulnerable Linux kernel. I'm simply wondering the telltale signs if a given system has been hacked? What, specifically, does a person look for? Thanks. Scott

Hi, I get ssh connect attempts all the time, to my servers at home and at work. I've noticed lately they come from a certain ip address, hitting every 3 or 4 seconds, trying 50 or 100 different user names and passwords. And I get these sweeps from 2 or 3 ip addresses a day. I guess this is an automated attempt to guess a user/pass and break into a system. I tried to secure ssh better by

I''d like to hear some suggestions about securely administering a system remotely. Here''s the application: a project is going to scatter some server machines around the US. The server machines will be running Linux, with the only network servers being a custom application. Ignoring the separate question of physical security, how can I remotely check the system''s

Dear Friend, I done configuration using RBLSMTPD with WHITELIST, but I don't know it is correct. Please check files below are corrects. Thanks Adriano === FILE WHITELIST.DOMINIO.RBL. ==== $ttl 900 whitelist.dominio.rbl. IN SOA host1.xxxxxx.com. root.xxxxx.com. ( 2006112002 ; serial; 3600 ; refresh period (1 hora); 900 ; retry time (15 minutos); 1800 ; expire tiem (30 minutos); 900 ;

Does anyone know if there are plans to give sshd the ability to block further login attempts from a particular IP address/block after a set number of failed logins? I'm sure lots of other admins have seen their system logs full of attempts by hackers probing with lists of sample usernames. I know there is a Python script which uses TCP wappers to achieve this by editing

I got some weird mail back, claiming that my e-mail was blocked, w/o indicating what server was blocked, after the mail appeared in the mailing list. Is this some BS shakedown? I use postfix on a DSL line forwarding to earthlink, this is hardly something that should be rare in the BSD world... the mail appeared to come from a web mail server and the first link has the following lovely text:

Hey Guys, today I upgraded to 4.8-RELEASE-p15. As usual I set IPFIREWALL to default accept in my kernel config file. Config & make weren't complaining so, installed the kernel, reboot and there it was: >IP packet filtering initialized, divert disabled, rule-based forwarding enabled, default to deny, logging disabled Another rebuild didn't work out so... I reviewed

Hi Everyone, Before I begin, I'd just like to mention: I love dovecot. Thank you :) Anyway, today I had 8000 login attempts to my dovecot server in an hour before blocking the IP with my firewall. After googling, I didn't see very much discussion on the topic. There was some mention of blocksshd which was supposed to support dovecot in the next release (but doesn't appear to) and

Hey everyone, After discussing the AllowGroups I think I've discovered a bug. The system is a solaris 8 system and the problem is that when I use AllowGroups with no AllowUsers args, the proper actions happen. Same with AllowUsers and no AllowGroups. When I try to combine the two, none of the Allow directives seem to take. Is it just me or maybe a bug? -James

Markus, ignore the other stuff I sent.. I need to go back to bed and stop trying to code.. <sigh> For everone else.. Will this make everyone happy? This does the follow. it will always honor AllowUsers. If there is no Allow/DenyGroups it stated they are not in allowUsers. IF there are AllowDenyGroups it tries them. And then stated they are not in either AllowUsers nor AllowGroups

Hi, I hope this is the right place for a feature request. I'd like to have more flexible AllowUsers/DenyUsers synax. I am in a situation, where I have machines connected to three networks (a private, high speed, a public, and a private vpn) and I'd like to enable root logins only on the private networks. Currently I see no way of doing this, because there is no way to specify a

Hi all, sometimes I?m checking status of my server with phpSysInfo, always is all right, but at May 8 I was experienced a "big deviation". My machine was online for 12 days, but net statistics are reseted. I was checked /proc/net/dev and there are reseted net statistics too. How is this possible? Just before I was experienced this problem I was updating two packages with yum

https://bugzilla.mindrot.org/show_bug.cgi?id=1690 Summary: AllowUsers and DenyGroups directives are not parsed in the order specified Product: Portable OpenSSH Version: 5.3p1 Platform: ix86 OS/Version: Linux Status: NEW Keywords: patch Severity: trivial Priority: P2 Component:

Hi there, I have just compiled openssh-5.0 on Solaris 10, and am trying to set up a certain pattern of user access control. Essentially, regular users should be able to login from any network, while root should be able to login only from a private network 192.168.88.0/22. Actually, for the purpose of sshd_config, this is four networks, but that's another story... Here is what I tried:

Hi list! I have some machines running openssh 3.9p1. AllowUsers is set to my users, that are allowed to login. If I set PermitRoot without-password, but do not include root in AllowUsers, root is not able to login with pubkey. I do not want to set root in AllowUsers, since the without-password option should check this allready, I think... So I made a small patch that allows me to login as root