Channel Register

Black hats attack gaping DNS hole

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nick

Whaaat 

Coat

I was extecting to read a story about people in bowler/top hats & other rediculous headgear to be invading t'internet. Oh well.

Neil Woolford

PlusNet look to be patched. 

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s-oarc.net reckon "212.159.6.113 appears to have GREAT source port randomness and GREAT transaction ID randomness"

The Kaminsky page reckoned ok as well, but without the nice scatter plots and GREAT CAPITALISATION.

Dave Morgan

Eclipse seems Ok 

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1. 212.104.130.65 (resolver2.th.eclipse.net.uk) appears to have GREAT source port randomness and GREAT transaction ID randomness.

2. 212.104.128.102 (uplink2-bba1.th.eclipse.net.uk) appears to have GREAT source port randomness and GREAT transaction ID randomness.

Test time: 2008-07-31 18:36:45 UTC

bob, mon!

shure, Y nought? 

Go

ISP - Verizon (buncha scumbagz)

DNS resolvers - 71.242.0.39, 71.242.0.36

Doxpara and DNS-OARC basically agree that my ISP's DNS servers are okay, but my local NAT router isn't randomizing the source ports very well.

My router is a re-imaged Linksys - guess I better get around to updating it :-(

(Icon? "Proceed with this nonsense at flank speed!")

Alan

gasp 

Well no one ever implied that Dan Kaminsky was the first person to know about these vulnerabilities. He made them public, and the bad guys are just getting their returns in while the getting is good. Who knows how long these holes have been in use for.

Anonymous Coward

Virgin Media 

Came back as safe from doxpara.

dns-oarc gave the following :

1. 194.168.8.110 (winn-dnsbep-2.server.virginmedia.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

2. 194.168.8.109 (winn-dnsbep-1.server.virginmedia.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

3. 62.254.32.148 (belf-dnsany-1.server.virginmedia.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

Pretty middle of the road then.

David Jones

BT Broadband 

Dead Vulture

DNS Resolver(s) Tested:

1. 194.74.65.68 (ns6.bt.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

2. 194.72.9.34 (bcn.customer.bt.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

Test time: 2008-07-31 18:49:17 UTC

Richard Conto

Comcast - Great Lakes Region 

https://www.dns-oarc.net/oarc/services/dnsentropy

DNS Resolver(s) Tested:

68.87.72.131 (chic-cns01.area4.il.chicago.comcast.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

68.87.77.131 (detr-cns01.westlandrdc.mi.michigan.comcast.net) appears to have

POOR source port randomness and GREAT transaction ID randomness.

68.87.72.133 (chic-cns03.area4.il.chicago.comcast.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

Test time: 2008-07-31 18:37:53 UTC

---

When I changed my DNS forwarder to one I knew was patched, it reported GREAT GREAT.

---

DOXPARA said that things were good, and only reported ONE of the DNS servers I forward to.

Test Man

ADSL24 

Happy

"195.74.113.58 (ths-dns-cache1.enta.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

195.74.113.62 (ths-dns-cache2.enta.net) appears to have GREAT source port randomness and GREAT transaction ID randomness."

So this is good then?

Andrew Tyler

Road Runner 

Time Warner ( Road Runner) - 65.24.7.3

GREAT/GREAT at DNSOARC

DoxPara - Looks good to me. I guess.

ben edwards

eek 

How do we really know doxpora is legit? We'd be freely giving away the names of our DNS servers, and easily too!

Kincaid

OpenDNS 

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I saw that Time Warner & Roadrunner were both deemed unpatched the last I checked. I use OpenDNS instead which is protected according to the DoxPara DNS Checker.

Lee T.

aanet - australia adsl 

Go

great/great/great/great

great.

Glenn Booth

Well done Zen. 

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I didn't expect anything different, but Zen Internet's DNS services are all in the green. I hit both 212.23.3.100 and 212.23.6.100 - they've done their job; source port randomness abounds.

Toodle pip.

Martin Sylvester

Plusnet scoring "GREAT" 

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"1. 212.159.6.101 appears to have GREAT source port randomness and GREAT transaction ID randomness.

"2. 212.159.6.97 appears to have GREAT source port randomness and GREAT transaction ID randomness.

"Test time: 2008-07-31 20:08:11 UTC"

Anonymous Coward

How do we know this is his exploit 

DNS gets attacked all the time, maybe someone else just spilled their version.

He should have created a encrypted file with the details and publicly posted it.

So who knows.

Thing is people will use the known exploits just as they emerge, the chaos helps to cover tracks. I still think what he has done is a bit irresponsible, DNSSEC has been preventing these attacks for a while, and the latest bind patch was available before this went public. So, what we have here is a known attack given a lot of publicity.

Well, if the sec guys can keep up with the numbers, they may find quite a few of the crackers, but this has upped the volume.

Colin Morris

OK! 

Paris Hilton

Yep, Zen Internet seem to know what time it is!

Paris, cos she's safe too...

Anonymous Coward

Verizon 

Dead Vulture

DNS Resolver(s) Tested:

68.238.112.36 appears to have POOR source port randomness and GREAT transaction ID randomness.

68.238.96.38 appears to have POOR source port randomness and GREAT transaction ID randomness.

68.238.96.37 appears to have POOR source port randomness and GREAT transaction ID randomness.

Ok, does this mean that redirection to a bogus site would still work?

Petr

Bellsouth (now AT&T) - South florida 

1. 205.152.132.31 appears to have GREAT source port randomness and GREAT transaction ID randomness.

2. 205.152.144.13 (oldmail1.mia.bellsouth.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

3. 209.244.5.159 (ics2.Atlanta1.Level3.net) appears to have GOOD source port randomness and GREAT transaction ID randomness.

Steve Evans (a different one)

Newnet seems to be ok 

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Newnet seems to be ok

Your name server, at 212.87.64.7, appears to be safe, but make sure the ports listed below aren't following an obvious pattern (:1001, :1002, :1003, or :30000, :30020, :30100...).

but how do I check the ports??

adnim

Clara 

1. 195.8.69.7 (resolver1.uk.clara.net) appears to have GOOD source port randomness and GREAT transaction ID randomness.

2. 80.168.69.20 (resolver3.clara.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

I like my ISP, not cheap, not throttled either. No apparent port blocking. Local call rate support. Just in case anyone wants to jump ship from any Phormised ISP.

No I am not a Clara employee ;-)

Robert Grant

Sky 

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1. 90.207.242.85 (5acff255.bb.sky.com) appears to have GREAT source port randomness and GREAT transaction ID randomness.

2. 90.207.242.82 (5acff252.bb.sky.com) appears to have GREAT source port randomness and GREAT transaction ID randomness.

3. 90.207.242.87 (5acff257.bb.sky.com) appears to have GREAT source port randomness and GREAT transaction ID randomness.

Chronos

Re: Verizon 

Yes, they're vulnerable. The transaction ID is irrelevant as it is guessed by the attacker with chances of a hit being one in 65536 per shot. The crux of the matter is a static upstream query port on the recursive server being queried, allowing the attacker to both send unique unresolvable queries within the target domain (1.example.com, 2.example.com...) to port 53 AND know which port the server is listening for an answer on. He then fires answers at it pretending to be the server the resolver is querying (remember, this is UDP. No state, easy to spoof, no reply needed once you get an answer accepted). You only need to guess the transaction ID correctly once and then you've polluted the cache for the entire example.com domain for however long you set that answer's TTL to (or the cache lifetime, whichever is smaller) by dint of in-bailiwick answers always being accepted for the whole domain. All the real example.com DNS servers will send back is NXDOMAIN, which doesn't get cached so you have, in effect, limitless query headroom to get the transaction ID correct without the risk of the real servers populating the cache first.

What the patch does is enable the server to use a random source port for every query in a recursive search, spoiling the cracker's ability to track which port the server expects a response on, thus giving the cracker no opportunity to insert his own bogus answers. It is, unfortunately, security by obscurity. We need signed roots and DNSSec. DNS is and always has been insecure. It's only a matter of time before more holes are found and this whole song and dance commences yet again. Of course, that implies ISPs will care enough to set up trust anchors, but that's a discussion for another day.

By the way, if anyone thinks adding 1 IN A x.x.x.x, 2 IN A x.x.x.x etc. to their zones is a defence, just ponder the use of very small shell scripts, uuidgen and sed to create the hostnames to query. I'm sure you'll agree that this idea is no defence at all. The hostname used is just a simple way of explaining the exploit. Even your run-of-the-mill skiddie isn't going to be that obliging. Patch. Now.

Mark McC

Tiscali 

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212.139.132.41/42 both scored great on all fronts. Which is surprising, because everything else about them is a bit pants.

robert

gentoo portage up to date? 

Ive just emerged the latest version of BIND from portage on my nameservers (9.4.2-P1) and restarted the service but im still getting:

(...co.uk) appears to have POOR source port randomness and GREAT transaction ID randomness

Trix

@ robert - GIYF 

Boffin

After a whole 3 seconds of Googling, I found this page on the Gentoo site:

http://www.gentoo.org/security/en/glsa/glsa-200807-08.xml

'All BIND users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync

# emerge --ask --oneshot --verbose ">=net-dns/bind-9.4.2_p1"

Note: In order to utilize the query port randomization to mitigate the weakness, you need to make sure that your network setup allows the DNS server to use random source ports for query and that you have not set a fixed query port via the "query-source port" directive in the BIND configuration.'

So did you check your "query-source port" directive in BIND?

grant warkentin

Open DNS tested okay 

Open DNS tested okay

1. 208.67.216.13 (bld3.sea.opendns.com) appears to have GREAT source port randomness and GREAT transaction ID randomness.

Kanhef

Verizon DNSs 

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141.154.0.68 (gtebo.ba-dsg.net)

141.155.0.68 (gteny.ba-dsg.net)

151.197.0.39 (home4.bellatlantic.net)

151.198.0.39 (home5.bellatlantic.net)

151.201.0.39 (home6.bellatlantic.net)

151.202.0.85 (nyc2-qwest.bellatlantic.net)

151.203.0.85 (boston2-qwest.bellatlantic.net)

All come up with poor source port randomness, great transaction ID randomness.

J. Simon van der Walt

Orange UK 

dns-oarc.net gives Orange UK;

193.36.79.101 Source Port Randomness: GREAT

193.36.79.101 Transaction ID Randomness: GREAT

but at doxpara.com the test doesn't seem to work; get a 'page not found'

Old Man - Grey Fleece

Demon 

Go

Appears to be patched

Stewart Midwinter

Shaw Cable ok 

1. 64.187.29.134 (h64-187-29-134.gtcust.grouptelecom.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

2. 64.59.135.133 (nsc1.so.cg.shawcable.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

3. 64.59.135.135 (nsc2.so.cg.shawcable.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

Anonymous Coward

@ Chronos 

Dead Vulture

Re: Verizon

Thanks for the explaination about port versus transaction randomness.

The thing about all this that really boils my bottom is that even though I have bothered with a home router, firewall, anti-virus and such for years my IS-freaking-P's unpatched DNS could render such preparations moot.

Alas, poor internet, I knew it Horatio. A place of infinite wit and zest.<holding 4-port router, talking to it>

when_the_sh*t_hits_the_fanboi

Oops - Nildram still vulnerable 

Your name server, at 213.208.106.212, appears vulnerable to DNS Cache Poisoning.

All requests came from the following source port: 33542

System Administrator

BT Broadband 

Linux

DIG: "62.6.40.162 [indnsc70.ukcore.bt.net.] is POOR: 26 queries in 3.8 seconds from 25 ports with std dev 271"

WEB Version: POOR source port randomness GREAT transaction ID randomness.

I get the POOR source port warning whatever test I use. I run my own LAN and LAMP setup via my otherwise vanilla BT Broadband connection (via HomeHub).

I suspect other factors rather than BT's DNS may be involved in the results - it would be great if someone could give us a clue and briefly explain what may restrict source port randomness. I have a clue (NAT/Firewall etc) but some folk out there actually 'know' :-)

OR - should I rely on the test and BT *are* actually POOR/GREAT rated!

Andrew McAuley

BeThere 

Happy

1. 87.194.0.51 (cache0.betherenow.co.uk) appears to have GREAT source port randomness and GREAT transaction ID randomness.

2. 87.194.0.52 (cache1.betherenow.co.uk) appears to have GREAT source port randomness and GREAT transaction ID randomness.

Theresa Jayne Forster

Bit worrying 

Paris Hilton

Well when i test on BOTH sites i get Problem Loading page, Server cannot be found

Sky Broadband....

Is this good or bad?

Kibble

Earthlink seems to be all right 

Happy

Using my usual local dialup number:

Your name server, at 209.179.23.207, appears to be safe, but make sure the ports listed below aren't following an obvious pattern (:1001, :1002, :1003, or :30000, :30020, :30100...).

@ Steve Evans

I don't know how to check the ports either.

Anonymous Coward

Sprint PCS, patched! 

Happy

68.28.250.92 (ns2.atlngar03.spcsdns.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

68.28.242.91 (ns1.atlngar03.spcsdns.net) appears to have GREAT source port randomness and GREAT transaction ID randomness.

Test time: 2008-08-01 07:24:35 UTC

For my wireless broadband, Sprint fixed it within the last week.

For my Verizon woes, I have pointed my router to OpenDNS, as opposed to letting my ISP do my DNS and that works just fine.

Thanks again to Chronos, et al, for the information. Yet another reason to love El Reg.

Anonymous Coward

Pipex 

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GREAT/GREAT

Goat Jam

OpenDNS 

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I haven't used my ISP's dns server for ages. OpenDNS is the way to go.

Dave Harris

TMNet (Malaysia) 

1. 203.121.16.85 (ns1.time.net.my) appears to have POOR source port randomness and GREAT transaction ID randomness.

2. 203.121.64.59 appears to have GOOD source port randomness and GREAT transaction ID randomness.

mdubh

Re: gentoo portage up to date? 

@robert

BIND 9.4.2-P1 should be immune to this issue:

http://www.isc.org/sw/bind/bind-security.php#matrix

Is your DNS server behind a proxy firewall or NAT device that is de-randomizing the source ports?

http://support.microsoft.com/kb/956190

Subs McNubs

BT - No suprises 

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1. 194.72.6.57 (ns3.bt.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

2. 217.169.46.108 (217-169-46-108.bis-internet.co.uk) appears to have UNKNOWN source port randomness and UNKNOWN transaction ID randomness.

Oh dear.

Tom Smith

Mistral 

217.154.96.244 (adsl-217-154-96-244.mistral.co.uk) appears to have GREAT source port randomness and GREAT transaction ID randomness

So that's alright then :)

and I use OpenDNS at home.

Rob Simmonds

Aquiss 

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Are Great all round according to the tester.

Which is nice...

AlfieUK

BT Business Broadband 

Via dns-oarc.net;

1. 194.72.9.34 (ns5.bt.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

2. 62.6.40.178 (indnsc71.ukcore.bt.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

...and...

1. 194.72.9.34 (bcn.customer.bt.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

1. 194.72.9.34 (indnsc30.ukcore.bt.net) appears to have POOR source port randomness and GREAT transaction ID randomness.

Anonymous Coward

nildram fail 

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Name servers 213.208.106.212, 213.208.106.213

Wokstation

Title 

"Your ISP's name server, 80.3.128.148, has other protections above and beyond port randomization against the recently discovered DNS flaws. There is no reason to be concerned about the results seen below.Requests seen for a563cec7b068.doxdns5.com:

80.3.128.148:33383 TXID=33827

80.3.128.148:33421 TXID=26554

80.3.128.148:33406 TXID=40195

80.3.128.148:33373 TXID=9963

80.3.128.148:33330 TXID=37889

ISNOM:ISNOM TXID=ISNOM "

From Tesco.net, a Virgin reseller.

Chronos

Re: gentoo portage up to date? 

Check your named.conf for "query_source" and remove/comment that line. Other possible causes are the rc script calling rndc reconfig rather than kill/exec, which will leave the running process resident and just cause it to re-read the config. Manually /etc/init.d/named zap && /etc/init.d/named start (or is it /etc/init.d/dns on Genitals? I forget...) as big bad root. You may also have a firewall/router in the path of the 'net connection undoing all your nice port randomness.

Mal Franks

Andrews & Arnold 

81.187.81.41 (lifeless.aaisp.net.uk) appears to have GREAT source port randomness and GREAT transaction ID randomness

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