Kerberos bug means one set of credentials suffices to rule them all.
If you are a
Windows
systems administrator, the content of this blog post will (hopefully) not come as a surprise. If it does, you should finish reading it quickly and make some time to apply the out-of-band patch
MS14-068
to all
Windows
systems under your control as soon as possible.
The patch fixes CVE-2014-6324, a checksum vulnerability in the
Kerberos
authentication protocol. It means that anyone with a user account on a local domain could elevate privileges to those of the domain administrator account.
The Kerberos protocol. Source:
Wikimedia Commons
.
The vulnerability has been rated ‘critical’, the highest possible severity rating, which is uncommon for privilege escalation vulnerabilities. However, the rating appears to be justified, as the vulnerability can be exploited remotely. It means that an attacker targeting an organization’s network only needs to get hold of one valid set of credentials to take full control of the domain.
Indeed,
Microsoft
reports that the bug has already been exploited in targeted attacks in the wild.
MS14-068 means an intern can get access to the CEO’s office by holding his thumb over the photo on his ID-card. While working from home.— Martijn Grooten (@martijn_grooten)
November 18, 2014
In a
blog post
giving more details on the vulnerability,
Microsoft
engineer Joe Bialek advises that domain controllers running
Windows Server
2008R2 and below should be given the highest priority, but says that all
Windows
versions should be fixed as soon as possible.
Should a domain already have been compromised, the only way for this to be remediated is a complete rebuild of the domain.
Posted on 19 November 2014 by
Martijn Grooten
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