Gmail As Open-Relay Spam Server 145
sveard writes of a little problem Google is having that has Gmail acting like an open relay. Compounding the issue is the fact that services such as Hotmail and Yahoo trust Gmail as a source of mail. "A recently-discovered flaw in Gmail is capable of turning Google's e-mail service into a highly effective spam machine. According to the Information Security Research Team (INSERT), Gmail is susceptible to a man-in-the-middle attack that allows a spammer to send thousands of bulk e-mails through Google's SMTP service without fear of detection. This attack bypasses both Google's identity fraud protection mechanisms and the current 500-address limit on bulk e-mail."
doesn't stop spam, (Score:2, Insightful)
You should have known (Score:4, Funny)
Wow, slashdot doesnt give a crap (Score:2, Informative)
But, on topic, this really isn't all the surprising. Pretty much any email server can be used as a relay in this manner, the only thing special here is that it avoids Google's current features. I expect Google will have this locked down very soon.
Re:Wow, slashdot doesnt give a crap (Score:4, Interesting)
Certainly, but this can be reduced by making sure that e-mail coming from the outside world can only be sent to gmail addresses and e-mail going to the outside world requires password authentication by the sender. One issue that we are starting to see it e-mail being bounced to a different part than the one that officially sent the e-mail. Other measures that can help is only accepting e-mail from external mail servers who's name can be resolved from its address.
The real problem is really deciding what is a legitimate source of e-mail, without requiring a central registry of e-mail servers or some other sort of bureaucratic process.
Re:Wow, slashdot doesnt give a crap (Score:5, Insightful)
The other problem is, Hotmail and Yahoo trusting Gmail. In the world of email, there is no such thing as a trustworthy server.
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Re:Wow, slashdot doesnt give a crap (Score:5, Insightful)
> source of e-mail, without requiring a central registry of
> e-mail servers or some other sort of bureaucratic process.
Well that's the problem that SPF solves. Each domain owner
creates a DNS entry that specifies which mail servers are
permitted to send mail for that domain. When an MX receives
a HELO it checks that the originating IP corresponds with
the DNS entry; if not, the mail can be rejected or subjected
to further inspection and scoring.
Simple to implement, I've done it in 20 minutes for my domain
( 20 minutes from ``What is this project?'' to submitting the
DNS change ).
http://www.openspf.org/ [openspf.org]
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I don't understand how there are really that many network/system admins out there that don't understand how the Internet works.
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I'm guessing giving these guys a million dollars and saying 'make spam stop globally' might just work.
It's worth a try.
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Certainly, but this can be reduced by making sure that e-mail coming from the outside world can only be sent to gmail addresses and e-mail going to the outside world requires password authentication by the sender.
And, specifically, that it can only be sent to valid Gmail addresses.
I've done stuff like this with Postfix, in my spare time, on my own mailserver. It's trivially easy, and it completely eliminates bounces, except in the case of mysterious internal errors -- but even then, I think it's more common for a temporary error to be returned at the SMTP layer than for the mail to actually bounce.
Bounces are unnecessary, full stop.
Idiots better get off their ass (Score:5, Informative)
I have already checked my server logs and the fun just started a little while ago. Yay!....
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Re:Idiots better get off their ass (Score:5, Insightful)
In practice, however, Google is likely to do just that anyway, and since there is no organized blacklisting going on, a sole action by the GP poster would most likely annoy his users while Google itself wouldn't even notice it.
(Unless, of course, the GP happens to be the sysadmin for Hotmail, Yahoo! Mail or something similar - in that case: Blacklist, baby!
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Re:Idiots better get off their ass (Score:4, Insightful)
SpamCop and SpamHaus blocking Google? How do they say it... When Pigs Fly?
People that use both of those services, free and paying customers alike, rely on them automatically managing their lists. I am sure, and I am certainly adding myself to this, that "we" don't expect these services to add Hotmail, GMail, Yahoo, etc. You can also toss Comcast, AT&T, Time Warner's Roadrunner, Cox, etc. to the list too.
Unfortunately, there is such a thing as being too big to blacklist. I don't know how many millions of customers that it starts at, but GMail passed whatever mark that was a long time ago.
Organized blacklisting only applies to much much smaller entities.
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On a few mail installations I've done, it watches for abusers, and blocks them with firewall rules, based on other detections including SpamAssassin.
So even my own mail system would block gmail if it detects enough spam coming from them. The threshold is high enough to not false, and low enough to stop most of the badguys. On a typical server (~50k msg/day) something like 1500 get blocked daily, with no complaints th
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First Youtube and then that. Indeed.
Interesting... (Score:5, Informative)
Because that's when the existence of the vulnerability was already known, at least. The people who figured it out aren't telling the world how to do it (I'm sure clever people can figure it out), and are / were waiting for Google to fix it first.
http://ece.uprm.edu/~andre/insert/gmail.html [uprm.edu]
You might be seeing plain ol' spam from gmail; it's been having its share of problems with spammers since both captcha crack -and- before that by manual sign-up, simply -because- everybody trusted gmail (what, with the forced SMS/Text Message sign-up, invite-only, etc. preceding).
Re:Idiots better get off their ass (Score:4, Interesting)
Unfortunately, this sort of thing will continue to crop up. E-mail is fundamentally broken, and it's too easy to take advantage of any e-mail system. To combat spam, mail admins have had to take many unorthodox and RFC-bending practices (if not out-right ignoring RFCs all together). Otherwise, users complain about too much spam. The down side, users then complain about e-mail delays or non-deliverables. So, you get systems setting up certain ways to bypass filters for hopefully trusted domains. And then this whole new problem comes up when people figure out new ways to abuse the system, its safeguards, and hidden/implicit trusts.
Ugh. At this point, I just want to turn SMTP off completely. This is a losing battle.
Re:Idiots better get off their ass (Score:5, Interesting)
I hear this being said over and over again. The problem is that no one has been able to provide a solution to resolved the problem. There have been suggestions, but doing so without penalizing the small guy is hard. Do we require certificates and if we do how can we ensure that it will be 100% fool proof? Do we only accept e-mail that hasn't been relayed or only accept mail from white listed relays, or create rules for them, if relays are to be tolerated in certain conditions?
Re:Idiots better get off their ass (Score:4, Interesting)
There are trivial technical solutions for the spam problem if only we could get rid of SMTP.
Ofcourse "we" can't but my hopes are that google may do it eventually. They could roll out a new system on a large enough scale to actually make it stick.
Re:Idiots better get off their ass (Score:5, Insightful)
Spam exists because there are sociopaths who want to steal resources from others. There is *NO* technical solution to this. If your SMTP replacement allows anyone to contact anyone else, it will allow spammers to contact anyone.
Spam is a social problem, not a technical one. There is no such thing as a technical solution to a social problem.
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Re:Idiots better get off their ass (Score:4, Insightful)
Cost, plain and simple. The fundamental way to reduce spam is to make it cost more to do. Of course actually figuring out a good way to do that is left as an exercise for the reader.
Re:Idiots better get off their ass (Score:4, Insightful)
Thank you for illustrating my point.
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Simply extending the junk fax law to cover email spam would be easy. The money saved in dealing with people's incoming spam would be more than enough to do the necessary enforcement of the laws, with such a cl
Internet Laws mean little... (Score:2)
Re:Idiots better get off their ass (Score:5, Insightful)
That's generally true.
The problem is that SMTP makes it drastically worse than it needs to be with a push model. The spammer can send a million messages, and they've all already been accepted by the destination server before anyone has a chance to complain.
If it were a notification / pull model then when someone complained the ISP could pull the spammer's plug for a TOS violation before most of the messages in his first batch were delivered. Sure, that doesn't kill the spam problem utterly dead - but it does mean that current spam management resources could keep it down to well under 90% of all email.
Re:Idiots better get off their ass (Score:4, Insightful)
The thing is that we can already achieve the same effect through a combination of greylisting and a trustworthy blacklist: an unknown (non-whitelisted) sender cannot deliver messages immediately, and if they're one of the few spammers who will retry deliver after a temporary failure, then by that time odds are that they will have been blacklisted.
Sure, it's possible that a pull model might prove slightly more effective even so, but neither model will ever kill spam dead. And "possibly slightly better at dealing with spam, but probably just the same" isn't nearly enough to justify uprooting the world's entire email infrastructure.
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before anyone has a chance to complain.
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Spambots would not function any more. I don't know why this is so difficult to put in place.
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One trivial approach would be mandatory message signing (cryptographic identity) combined with challenge/response.
Whenever someone wants to mail you for the first time your mail server would, depending on your preference, either ask them to solve a captcha or you to permit mail from that sender.
From that point on the sending identity would be on your whitelist and you could exchange mail freely.
This can be built today, on top of freely
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One trivial approach would be mandatory message signing (cryptographic identity) combined with challenge/response. Whenever someone wants to mail you for the first time your mail server would, depending on your preference, either ask them to solve a captcha or you to permit mail from that sender.
While challenge/response is a sure-fire solution to spam technologically, it utterly fails on the social level. Most people HATE challenge/response. Many web sites specifically state that their operators will not
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Yes, C/R is annoying when you have to sift through your mailbox to separate spam from Challenges. When they look like any other E-Mail with not even a standard formatting to identify them. When the procedure varies between clicking a link, replying or even quoting some gibberish text from the mail (oh and don't get it wrong or it won't work), etc.
C/R would be widely accepted if you think more
Re:Idiots better get off their ass (Score:4, Interesting)
C/R is annoying because people want their messages to be delivered, without additional work. It's not even that I have to scan a spambox, or that they look like any other e-mail. It's that I have do to ONE MORE THING to have the message delivered. If this had been the way e-mail worked originally, then people might accept it; but now, everyone is used to sending e-mail and having it arrive without interruption (generally speaking).
Respectfully, I'm pretty convinced that it will not work unless the spam problem becomes so excessively bad that people are willing to change their e-mail habits. We are not yet to that point, thanks to all the other half-baked anti-spam solutions out there.
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Well, I guess we have to agree to disagree. "Without additional work" is ign
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Yes, we'll have to disagree. It is alright.
This risk is not solved by C/R, unfortunately.
I've been sending and receiving e-mails for nearly 30 years, I have more than a dozen e-mail accounts and hundreds more e-mail
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Sending C/R challenges to forged senders IS SPAM. Offloading your problem onto everyone else is not solving it.
Re:Idiots better get off their ass (Score:5, Interesting)
This is like complaining that wheels don't protect against being rained on, so cars should be redesigned from scratch.
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I can tell you why: because it's not that easy.
The fundamental building blocks for any technical solution to the spam problem are sender identity and challenge/response. Neither can be implemented on top of SMTP. Neither can be implemented as an extension to SMTP without incompatible changes to the protocol semantics.
If you want to insist that SMTP is "not broken" then please present your solution for
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I disagree. The problem simply is not well defined. Everybody claims the spam problem is slightly different, and nobody agrees what spam actually is and what spam isn't. That's why it hasn't been "solved" to everybody's satisfaction. There are plenty of partial solutions for specific issues that specific people have, and for many people the
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For 99% of us spam is defined as: Stupid advertisement that I have never requested.
Yes, there are corner cases but claiming that the problem is not well defined not only ignores years of research into that area, it also ignores common sense.
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Yes, that's one definition useful for individual users, but not very useful for mail admins. In particular, it leads to inconsistent spam definitions at the level of an organization, because as the number of people increases, the number and types of emails wanted by some (=ham) and not wanted by others (=spam) increases.
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1. Admins would not have to keep the identity lists at the MTA up to date. The users do that themselves (their MUA interfaces with the MTA).
2. Trying to implement all this at the MUA level would mean adoption problems (chicken/egg) and networks/servers still bogged down with garbage traffic.
3. The individual definition of spam doesn't matter. Every user grows their own whitelist which would live primarily in the MUA (maybe bundled with that private key file for easy export) and a
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They'll already balk at just keeping any identity list for each user, let alone an updated one :)
However, a filtering setup within a MUA is a kind of identity list already.
It does if you expect admins to do some filtering work for the users
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I have my own domain, but don't host it myself. My email goes through my hosting company's smtp server, with my address @ my domain. I'm sure there are thousands, if not tens of thousands of other legitmate users like me doing the same thing. If you block all mail that's been relayed, none of us will be able to get email to you. There must be a better way...
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People would get whatever certificates etc they need from their messaging provider which would be a similar person to their existing email provider.
The problem of course is persuading people to use it, and people won't use it if nobody else is using it.
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The problem is that no one has been able to provide a solution
E-mail is fundamentally broken
In other words, it is fundamentally broken, because it is fundamentally unfixable.
Interestingly however, I would like to argue for the exact opposite. The original intent and nature of email was to be completely open. The fact that it is so *perfect* at being open has made it *impossible* to close parts of it that are no longer desired.
As problem solvers we like to think we can solve problems with solutions, but this is a case where we are
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It penalizes the big guys instead of the small guys, that's why it hasn't taken off. Also, no one seems to want to promote any solution that doesn't put somebody in control of something.
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Re:Idiots better get off their ass (Score:4, Informative)
Re:Idiots better get off their ass (Score:4, Insightful)
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Re:Idiots better get off their ass (Score:5, Informative)
The spammers don't care about what their FROM and REPLYTO fields actually say. Since this is a man-in-the-middle attack they could put practically anything with a @gmail.com in those fields and it will render your solution ineffective.
The real problem with this exploit is that it bypasses all of Google's security measures and anything I could do on my end would only verify that the email actually came from a real Google mail server and from a Google email user. So then I can only rely on SPAM filtering based on content which is not as effective as we would all like it to be.
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Re:Idiots better get off their ass (Score:4, Informative)
Won't work.
There are boatloads of people and companies using Google with their own domains. Google Apps, Google Enterprise, etc.
Also, many of the spammers are using gmail addresses. Remember, they don't care about return emails, they just drive people to their websites.
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Also, for people in England, you will have to allow googlemail.com. Google isn't allowed to use gmail here as someone else owns the trademark.
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Why is that exactly? I'm not flaming, I'm genuinely curious. Every business I do work with has their own email system, and the thought of someone using Gmail for business use give me goosebumps so I am not sure blocking it would impact most organizations all that much.
I asked because I don't know why you couldn't temporarily block it. If everyone did then Google would be motivated to fix the problem
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The customer does not care about Google and Relaying or any other techno gobbletly gook. They only care that email was being blocked. It is not even a GMail specific thing either. It can be ANYBODY not being able to communicate to them, real or imagined, a
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Whitelists don't work. (Score:5, Insightful)
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A proper white list shouldn't include sites which are likely to be insecure, and it shouldn't grant a completely free pass either. Whitelisted domains do still get submitted to checks on well secured servers. DKIM and SPF being pretty much mandatory these days, as well as virus scanning and spam rating as well.
Really the po
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If so, then what's the use having them? A whitelist is supposed to be a list of trusted addresses or domains, isn't it? If you still have to run them through your spam filter, isn't it a waste of time having one?
Whitelisting is just a means of filtering out as many known bad domains as possible before using more expensive scanning and verification technology.
No, that's not what a whitelist is for. That's a blacklist you'
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Chronologically impaired? (Score:2, Informative)
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Funny thing... (Score:2, Insightful)
They'll fix it if it gets enough bad publicity (Score:5, Insightful)
Bad publicity made Google fix their open redirector for URLs. Bad publicity will make them fix this.
GMail ought to go back to cell phone authentication for new accounts. Since their capcha was broken, they've become a favorite of spammers.
Blogspot is also a spam haven. Most blogspot blogs are spam, and they can be used as a form of open redirector. Look for spams like: "An IWC watch is a uniquely handcrafted time piece ... http://rexefute51720.blogspot.com/ [blogspot.com]"
Complain loudly, publicly, and often. Google needs to take stronger steps to avoid being a spam conduit.
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> URLs. Bad publicity will make them fix this
Your optimism is like a ray of Sunlight in a dark world, but I
fear it is misplaced.
Many USENET groups are virtually unreadable today because of the
torrent of spam posting originating from Google Groups accounts.
Thousands of users have submitted precise spam reports to Google,
quoting the article-IDs. Result? None. Consequence? USENETters
start to block any and all Google Groups postings
( thou
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GMail ought to go back to cell phone authentication for new accounts.
I'm not sure if there's something similar in the US, but in South Africa I can get a mobile SIM card with a phone number capable of receiving calls and text messages for less than the equivalent of US$0.30. They're usually around the checkout counters at large retailers and the number activates automatically in less than 10 minute. It's well-known here that they are used by fraudsters when they want to do any phone-based verification.
Luckily we can tell which numbers are mobile numbers by the first th
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While everyone doesn't have a cell, it really fits into the demographic of people using gmail.
Bad Publicity? Ya THink? (Score:2)
Goddamned bastards have everything I send to my girlfriend from Google labeled as spam. The IT guy at her firm is a douche bag, but in this case it looks like he might be right.
Google needs to clean up its act.
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Just a Proof of Concept (Score:2)
The major problem with spam is quite simple: Spam is dirt cheap. I can send out a million spam messages for nothing. As long as I can do that, almost nothing w
Ok, this is how it works.. (Score:3, Insightful)
"If you want everybody to to be able to contact you, then you will receive information you do not want."
Conversely, if you have a system where the recipient requests information ( such as for web-pages ) then you have the following problem:
"I you want everybody to be able to get information about yourself, then people you don't like could collect information about you."
There's no way around these very simple facts, the best you can do is to change what you expect from the service. As an example e-mail spam would be rapidly defeated if you limited yourself to only receive information from sources you have approved in advance, but that is to limited for most people. Because we want our friends to be able to give our e-mail addresses to their friends if they have something nice to tell us. Therefore we will get e-mails we don't want. If you want to change this you have to either change your expectations of what e-mail should do, or you have to change the behavior of people sending out spam. The easiest way to do the latter is to penalize business who do it.
whitelisting is inherently wrong. (Score:2, Insightful)
Silly question (Score:4, Funny)
Re:DeBunking? (Score:5, Insightful)
i figure google will have this locked down soon enough though. It's not like they won't notice the sudden burst of traffic. Some guy is going to be working hard tonight.
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Well, this ruins GMail's major argument. nNw all they have left is "You get 2 GB of storage".
Huh? What argument are you refering to, and how does this ruin it?
The only "argument" I can think you might be refering to is that, by using Gmail, you avoid having to see a lot of spam due to their excellent spam filterings. This doesn't ruin that argument in any way. In fact, since it primary impacts sites like Yahoo and Hotmail (who will see more spam if they continue to whitelist Gmail), it strengthens it. You're now see even less spam using Gmail, comparatively speaking.
Re:Blacklist gmail (Score:4, Funny)
Yes, who would do business with such an entity. Probably about as many as would trust their business hosting to a company who declares its home page to be XHTML 1.1 but then serves it as text/html. Not to mention the 88 validation errors.
The point is you can't jump straight for the "nuclear" option. Although to be honest I wouldn't use such a Web host.
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The policy came up at review meetings, and was accepted company wide in several environments.
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teknopurge, you just got served.
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On our list of priorities the web-site w3 validation is right below our next marketing effort.
Regards,
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Sorry, that's wrong: http://www.w3.org/TR/xhtml-media-types/#summary [w3.org]
The only time you should serve XHTML as text/html is when it's XHTML 1.0, with special care taken to keep backward compatibility in mind.
And as for 88 errors, well, if you're not going to be valid, why declare a document type? This isn't difficult stuff. That's 88 more errors than there should be.
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Without standards you can't have real competition in the browser market, and it makes it harder to make websites. It's also not hard to write sites that have 0 errors.
Re:Blacklist gmail (Score:4, Funny)
http://validator.w3.org/check?verbose=1&uri=http://www.taylorbyrnes.org/ [w3.org]
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<h4>Red is Nagivation</h3>
<h4>CISPCA</h3>
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parent, INSIGHTFUL? (Score:3, Insightful)
You going to go an make some ideological bullshit point and piss all over your customers when it's not going to make the slightest difference to Google.
Go right ahead!
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