Ghost In The Machine: Database Weaknesses Expose SAP Deployments

Researchers last week announced glaring vulnerabilities in the way SAP interacts with the database layer that would allow remote attackers to own a company's SAP systems -- including controls that manage sensitive functions, such as vendor and invoice creation -- simply by compromising the database that lays at the heart of an SAP deployment.

Mariano Nunez Di Croce, a security researcher for Argentinean firm Onapsis, demonstrated how a malicious attacker can create a nearly undetectable ghost user account in SAP once he gains unauthorized access. According to Di Croce, that access can be gained by attacking vulnerabilities in any one of the layers that make up an integrated SAP deployment: the operating system layer, database layer, application layer, or SAP business layer.

Di Croce first revealed the flaws at Black Hat Europe earlier this year.

"No matter which of these layers he chooses, he will be able to compromise the whole platform," he explained in his presentation at Black Hat USA in Las Vegas last week. "SAP has a lot of internal trust relations in between the layers, so this is not a vulnerability in the platform [that can be patched]."

According to Di Croce, one of the biggest misconceptions that enterprises have about SAP systems is that their security is simply a function of implementing proper segregation of duties. Di Croce says he's on a mission to dispel that myth. He noted one security assessment he recently ran with a client that had spent buckets of cash to make its SAP implementation compliant with segregation of duties best practices, but which he was able to compromise in a matter of seconds.

He reported that SAP vulnerabilities are significantly on the rise, showing figures that SAP security notes for found vulnerabilities have risen from less than 50 in 2007 to more than 250 so far in 2010.

However, he believes the most likely layer within an SAP platform to be buffeted with an attack is the database, which is notoriously weak within the enterprise, particularly due to widespread use of default log ins.

"What an attacker will probably do is to go and attack directly SAP's heart, which is the database," he said. "He can exploit SAP plus Oracle application weakness, he can use one of the default user credentials for database access, [and] he can run a database exploit and take over the database."

This week Di Croce's company is releasing a free, new tool that helps detect the creation of ghost users within SAP systems. While the tool can be useful in fighting fraud within compromised systems, it is important to remember one critical fact.

"In order to install a back door, the attacker needs to compromise the system first," Di Croce says. Hardening database systems can go a long way toward preventing that first step from occurring.

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