Feeds

Critical flaw exposes Oracle database passwords

Vuln leaves barn door open to brute-force attacks

Choosing a cloud hosting partner with confidence

A security researcher says some versions of the Oracle database contain a vulnerability so serious that anyone with access to the server over a network can crack database passwords using a basic brute-force attack, given nothing more than the name of the database and a valid username.

"This is a critical issue because it's very easy to exploit, and it doesn't require any privileges," AppSec's Esteban Martinez Fayó said in an interview with Dark Reading.

According to a report issued on Thursday by Kaspersky Labs' Threatpost, the vulnerability stems from a fundamental flaw in the logon authentication protocol used by Oracle Database 11g Releases 1 and 2.

Normally, Oracle databases maintain connections with clients by issuing each a unique value known as a Session Key. But affected versions of Oracle 11g send the Session Key before the user is fully authenticated. As a result, an attacker can send a username, receive a Session Key, then hang up the connection and use the Session Key to guess the user's password.

"The attacker can perform a brute force attack on the Session Key by trying millions of passwords per second until the correct one is found," Fayó said, adding, "This is very similar to a SHA-1 password hash cracking."

According to Fayó, he and his team first alerted Oracle to the bug in May 2010. It was fixed in mid-2011, he says, but the patch was not included in a Critical Patch Update, and it only solved the problem by issuing a new, incompatible version of the authentication protocol, version 12.

Even when the patch is applied to a database, it will still use version 11.1 of the protocol by default. To get up and running with version 12, database servers and clients must both be patched, which means a large number of organizations are still using version 11.1 – and are therefore still vulnerable.

According to Fayó, Oracle currently has no plans to patch version 11.1 of the protocol to fix the flaw, and they aren't doing much to help customers migrate to version 12, either.

"The only comment from them was a paragraph about a new protocol fixing some security issues," he said. "They haven't said anything that made people aware to update the database and all of the database clients."

Mind you, brute-force attacks are not the easiest way to crack a password, since they essentially involve exhausting every possible combination of characters until the right combination is found. And Fayó says advanced cracking techniques, such as rainbow tables, can't be used to exploit this vulnerability, because of the way Oracle's cryptography is designed.

Still, he says, GPU acceleration and hybrid dictionary attacks can speed up the process of guessing passwords considerably, and Fayó has developed a proof-of-concept attack that can crack eight-character Oracle passwords in around five hours using standard CPUs.

In lieu of a fix from Oracle, Fayó recommends several work-arounds. One is to wrap database connections in some additional form of authentication, such as SSL or directory services. Another is to disable version 11.1 of the authentication protocol altogether and use an earlier version, such as 10g, which isn't vulnerable. ®

Beginner's guide to SSL certificates

More from The Register

next story
Russian hackers exploit 'Sandworm' bug 'to spy on NATO, EU PCs'
Fix imminent from Microsoft for Vista, Server 2008, other stuff
FYI: OS X Yosemite's Spotlight tells Apple EVERYTHING you're looking for
It's on by default – didn't you read the small print?
Microsoft pulls another dodgy patch
Redmond makes a hash of hashing add-on
'LulzSec leader Aush0k' found to be naughty boy not worthy of jail
15 months home detention leaves egg on feds' faces as they grab for more power
Forget passwords, let's use SELFIES, says Obama's cyber tsar
Michael Daniel wants to kill passwords dead
Kill off SSL 3.0 NOW: HTTPS savaged by vicious POODLE
Pull it out ASAP, it is SWISS CHEESE
Facebook slurps 'paste sites' for STOLEN passwords, sprinkles on hash and salt
Zuck's ad empire DOESN'T see details in plain text. Phew!
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.