Sendmail breached by new flaw

Daily Newsletters

Sign up to ZDNet UK's daily newsletter.

NEWS
A serious security vulnerability has been found in the ubiquitous Sendmail software, which processes 60 percent to 70 percent of the world's email messages. The flaw was discovered by US-based security researcher Michal Zalewski, and is separate from the one discovered by Internet Security Systems earlier this month. "I've confirmed this is a local issue, and my initial impression is that a remote attack possibility is not that unlikely," Zalewski said in a statement. The bug was found in the prescan() function, which is used to parse email addresses from incoming messages. By sending a malformed email message to a Sendmail server, it may be possible for a remote attacker to gain entry to vulnerable machines. US-based vulnerability coordination centre CERT claimed most companies are likely to be affected by the new glitch. "Most medium-sized to large organisations are likely to have at least one vulnerable Sendmail server," CERT said in an advisory. The advisory also pointed out that companies may not even know they are running Sendmail because it is enabled by default in many Unix and Linux distributions. Because the vulnerability is exploitable through malformed messages, companies using other software to relay mail to a Sendmail server on an internal network segment will also be affected. "An MTA (mail transfer agent) that does not contain the vulnerability will pass the malicious message along to other MTAs that may be protected at the network level... Sendmail servers on the interior of a network are still at risk," CERT said. Security researcher Matthew McGlashan, who is based at AusCERT at the University of Queensland, says that an exploit to the latest vulnerability isn't known to be circulating. "It's fairly new... there's more chance of attackers going after the first (flaw) rather than this," he said. But McGlashan said there's no point risking it -- companies running Sendmail should patch it as soon as possible. "In these situations, you just wouldn't take any chances... it's good practice (by mitigating) by patching if you can," he said. Alternatively, system administrators can run the Sendmail process as a low-level user instead of root, hence minimising the impact of the vulnerability, McGlashan said.
For all security-related news, including updates on the latest viruses, hacking exploits and patches, check out ZDNet UK's Security News Section. Let the editors know what you think in the Mailroom.

Post your comment

In order to post a comment you need to be registered and logged in.

You can also log in with Facebook. Log in or create your ZDNet UK account below

  • Login

Will not be displayed with your comment

By signing up for this service, you indicate that you agree to our Terms and Conditions and have read and understood our Privacy Policy. Questions about membership? Find the answers in the Community FAQ

Get ZDNet UK's daily newsletter

Enter your email address to sign up

ZDNet UK Live

BrownieBoy

@Jack, > Works really well for thieves.... Nice attempt to deflect the argument by tossing in a point that's totally irrelevant, even it were...

9 minutes ago by BrownieBoy on AMD Ultrathins to challenge Intel Ultrabooks
bootlegger

Make that 13 people now - I got refused today at Manchester airport. I thought I was up to date on this legislation - I knew of the EU ruling from...

3 hours ago by bootlegger on UK airport body scans will not be opt out
tinycg

Don't forget to check out apps like GoodReader or SlideShark either, they're indispensible for people on the go in presentation situations. Best...

6 hours ago by tinycg on Four top iPad apps for people on the move
TerryRK

Well it seems there is something a number of us agree on. Why is the Ubuntu Unity launcher so ugly? I thought perhaps it was something to do with...

10 hours ago by TerryRK on A tale of two distros: Ubuntu and Linux Mint
Freebies202

Duplicate comments are not made intentionally. Its very good to know that now you are keeping check on this problem because sometimes a commenter...

20 hours ago by Freebies202 on Microsoft fixes blog comments, speeds up blogs with open source
kevinmchapman

"the very significant number of users" and "many (most) of us" - you have no evidence for these statements. It is a fact that most users are saying...

1 day ago by kevinmchapman on A tale of two distros: Ubuntu and Linux Mint
Marg Menzies Harrison

Another grammar faux pas is the improper use of "you". When sitting down down in a restaurant, for example, I get cringe when the waitress...

1 day ago by Marg Menzies Harrison via Facebook on 10 flagrant grammar mistakes that make you look stupid
zdnetukuser

And NOW, folks, for Canonical's next trick... Kubuntu is late. Here's a pencil. Draw your own conclusions. cf.:...

1 day ago by zdnetukuser on Linux Minterface
Moley

@kevinmchapman. The discussion here reflects the very significant number of users who really do like the traditional menu system and who wish to...

1 day ago by Moley on A tale of two distros: Ubuntu and Linux Mint
kevinmchapman

Er, no... It is an efficient means of finding the application/file/setting you need in one place. The icons are a simply a fallback for when you...

1 day ago by kevinmchapman on A tale of two distros: Ubuntu and Linux Mint
TerryRK

Isn't the provision of a text based search an admission by the developers that the mass of icons approach does not work? I don't need to use a...

1 day ago by TerryRK on A tale of two distros: Ubuntu and Linux Mint
kevinmchapman

"Unity and GNOME 3 both abandon the old text-based cascading menus in favour of a graphical icon-driven system." Point truly missed. Both use a...

1 day ago by kevinmchapman on A tale of two distros: Ubuntu and Linux Mint
TerryRK

whs001 - Thank you, I'm glad you liked the article. I absolutely agree with you on your first point. I should perhaps have made it clearer that...

1 day ago by TerryRK on A tale of two distros: Ubuntu and Linux Mint
Dennis Nilsson

If we allow corporate interest to dictate the way our government circumvents due process against foreign entities then we should accept the same...

2 days ago by Dennis Nilsson via Facebook on ACTA stumbles in Germany
GHar123

I totally dislike pirating of works, I fear that artists will be deterred from creating works if they think that they are going to get ripped off....

2 days ago by GHar123 on ACTA stumbles in Germany
JCB33

How dare film makers, artists or anybody that invests in creativity stop us pirating their works for free. I want to be able to walk into my local...

2 days ago by JCB33 on ACTA stumbles in Germany
Moley

@GrueMaster. I prefer horses for courses rather than one size fits all. I, and I suspect most other computer users, do not really wish to have...

2 days ago by Moley on A tale of two distros: Ubuntu and Linux Mint
greycynic

The product that scares me every time I have to use it is the Office 2007 version of Excel. The first bug that I found was applying the median...

2 days ago by greycynic on Ten flawed products that derail productivity
GrueMaster

Nice review and very informative. One thing I'd like to add (in reply to whs001's 1st question), the main reason to have the same interface from...

2 days ago by GrueMaster on A tale of two distros: Ubuntu and Linux Mint
Frederick Wrigley

I'be been using Mint 12 since the RC came out, and I am far more happy with the Cinnamon, the Mate, and, yes (with extensions), theGnome 3...

2 days ago by Frederick Wrigley via Facebook on A tale of two distros: Ubuntu and Linux Mint