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From: Randy Bush <randy@psg.com>
To: "Kerin Millar" <kfm@plushkava.net>
Cc: netfilter@vger.kernel.org
Subject: Re: prefix len confusion
Date: Wed, 10 Jun 2026 10:19:39 -0700	[thread overview]
Message-ID: <m2ik7q1ff8.wl-randy@psg.com> (raw)
In-Reply-To: <ead376de-4dd5-4725-86df-bf7cf798b672@app.fastmail.com>

>> we also see this (distributed source) attack on proxmox clusters' web
>> interfaces
>>
>>     2026-06-07T02:01:39.274405+00:00 pv0 pvedaemon[2276]: 
>> authentication failure; rhost=::ffff:85.11.167.7 user=root@pam 
>> msg=Authentication failure
>>     2026-06-07T02:01:42.970943+00:00 pv0 pvedaemon[2277]: 
>> authentication failure; rhost=::ffff:85.11.167.7 user=root@pam 
>> msg=Authentication failure
>>
>> can we safely just add ffff::0 to the v6 bogon list?
> 
> It's an IPv4 address being logged in the form of an IPv4-mapped IPv6
> address. If you wish to block it, consider it as an ordinary IPv4
> address (85.11.167.7).

if nft treats it as an ipv4 addy, then the ipv4 filters should have
blocked, n'est-ce pas?

    tcp dport 8006 ip daddr $PROX4 drop

> For that reason, you should also be able to observe the packet(s) if
> you add a suitable tracing rule to the existing PREROUTING chain.

after pouting another cup

> That is, unless it is bridged traffic or does not traverse the
> firewall (as discussed previously).

no bridging.  we are hunting other holes in the attack surface.
using your prerouting hack to demonstrate the filtering is working
is a big help in focusing our efforts.

randy

  reply	other threads:[~2026-06-10 17:19 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-10  0:10 prefix len confusion Randy Bush
2026-06-10  0:51 ` Kerin Millar
2026-06-10  1:01   ` Randy Bush
2026-06-10  1:26     ` Kerin Millar
2026-06-10  1:32       ` Randy Bush
2026-06-10  1:38         ` Kerin Millar
2026-06-10 16:33       ` Randy Bush
2026-06-10 16:53         ` Kerin Millar
2026-06-10 17:19           ` Randy Bush [this message]
2026-06-10 18:02             ` Kerin Millar
2026-06-10 23:51               ` Sunny73Cr
2026-06-10 23:57                 ` Randy Bush
2026-06-11  0:06                   ` Sunny73Cr
2026-06-11  0:25                     ` Randy Bush
2026-06-11  1:05                 ` Kerin Millar
2026-06-11  1:12                   ` Randy Bush
2026-06-10  6:20     ` Reindl Harald
2026-06-10 10:09       ` Kerin Millar
2026-06-10 16:01       ` Randy Bush

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