qmail smtp-auth bug allows open relay
John Brown
jmbrown at chagresventures.com
Wed Jul 16 02:17:09 UTC 2003
Nope, I thought it might be operational in nature. ergo
spammers and others now scanning for qmail-smtp-auth patch
users and using those weak sites as a relay.
the issue is that those sites will PASS the current "open relay"
check tools and thus not be BLACK LISTED.
Hey, what a cool feature. Passes open-relay test, won't get
black listed, and can be used to relay spam.
this might cause more traffic,, more abuse complaints, more
headaches for those in operations...
ps: the URL is *from* the qmail list.
cheers,
john
On Mon, Jul 14, 2003 at 08:45:44PM -0800, W.D. McKinney wrote:
>
> John,
>
> Did you mean to post this on the qmail list per chance ?
>
> Dee
>
> On Mon, 2003-07-14 at 08:34, John Brown wrote:
> > seems that there are installs of the smtp-auth patch
> > to qmail that accept anything as a user name and password
> > and thus allow you to connect.
> >
> > http://marc.theaimsgroup.com/?l=qmail&m=105452174430616&w=2
> >
> > is one URL that talks about this.
> >
> > There has been an increase is what appears to be qmail based
> > open-relays over the last 5 days. Each of these servers
> > pass the normal suite of open-relay tests.
> >
> > Spammers are scanning for SMTP-AUTH and STARTTLS based
> > mail servers that may be misconfigured. Then using them
> > to send out their trash.
> >
> > Some early docs on setting up qmail based smtp-auth systems
> > had the config infor incorrect. This leads to /usr/bin/true
> > being used as the password checker. :(
> >
> > >From an operational perspective, I suspect we will see more
> > SMTP scans
> >
> > The basic test (see URL above) should get incorporated into
> > various open-relay testing scripts.
> >
> > cheers
> >
> > john brown
> > chagres technologies, inc
> >
> >
>
More information about the NANOG
mailing list