In the original Understanding and Selecting a Database Activity Monitoring Solution paper we discussed a number of Advanced Features for analysis and enforcement that have since largely become part of the standard feature set for DSP products. We covered monitoring, vulnerability assessment, and blocking, as the minimum feature set required for a Data Security Platform, and we find these in just about every product on the market. Today’s post will cover extensions of those core features, focusing on new methods of data analysis and protection, along with several operational capabilities needed for enterprise deployments. A key area where DSP extends DAM is in novel security features to protect databases and extend protection across other applications and data storage repositories.
In other words, these are some of the big differentiating features that affect which products you look at if you want anything beyond the basics, but they aren’t all in wide use.
Analysis and Protection
- Query Whitelisting: Query ‘whitelisting’ is where the DSP platform, working as an in-line reverse proxy for the database, only permits known SQL queries to pass through to the database. This is a form of blocking, as we discussed in the base architecture section. But traditional blocking techniques rely on query parameter and attribute analysis. This technique has two significant advantages. First is that detection is based on the structure of the query, matching the format of the
WHEREclauses, to determine if the query matches the approved list. Second is how the list of approved queries is generated. In most cases the DSP maps out the entire SQL grammar – in essence a list of every possible supported query – into binary search tree for super fast comparison. Alternatively, by monitoring application activity, the DSP platform can automatically mark which queries are permitted in baselining mode – of course the user can edit this list as needed. Any query not on the white list is logged and discarded – and never reaches the database. With this method of blocking false positives are very low and the majority of SQL injection attacks are automatically blocked. The downside is that the list of acceptable queries must be updated with each application change – otherwise legitimate requests are blocked.
- Dynamic Data Masking: Masking is a method of altering data so that the original data is obfuscated but the aggregate value is maintained. Essentially we substitute out individual bits of sensitive data and replace them with random values that look like the originals. For example we can substitute a list of customer names in a database with a random selection of names from a phone book. Several DSP platforms provide on-the-fly masking for sensitive data. Others detect and substitute sensitive information prior to insertion. There are several variations, each offering different security and performance benefits. This is different from the dedicated static data masking tools used to develop test and development databases from production systems.
- Application Activity Monitoring: Databases rarely exist in isolation – more often they are extensions of applications, but we tend to look at them as isolated components. Application Activity Monitoring adds the ability to watch application activity – not only the database queries that result from it. This information can be correlated between the application and the database to gain a clear picture of just how data is used at both levels, and to identify anomalies which indicate a security or compliance failure. There are two variations currently available on the market. The first is Web Application Firewalls, which protect applications from SQL injection, scripting, and other attacks on the application and/or database. WAFs are commonly used to monitor application traffic, but can be deployed in-line or out-of-band to block or reset connections, respectively. Some WAFs can integrate with DSPs to correlate activity between the two. The other form is monitoring of application specific events, such as SAP transaction codes. Some of these commands are evaluated by the application, using application logic in the database. In either case inspection of these events is performed in a single location, with alerts on odd behavior.
- File Activity Monitoring: Like DAM, FAM monitors and records all activity within designated file repositories at the user level and alerts on policy violations. Rather than
DELETEqueries, FAM records file opens, saves, deletions, and copies. For both security and compliance, this means you no longer care if data is structured or unstructured – you can define a consistent set of policies around data, not just database, usage. You can read more about FAM in Understanding and Selecting a File Activity Monitoring Solution.
- Query Rewrites: Another useful technique for protecting data and databases from malicious queries is query rewriting. Deployed through a reverse database proxy, incoming queries are evaluated for common attributes and query structure. If a query looks suspicious, or violates security policy, it is substituted with a similar authorized query. For example, a query that includes a column of Social Security numbers may be omitted from the results by removing that portion of the
FROMclause. Queries that include the highly suspect
WHEREclause may simply return the value
1. Rewriting queries protects application continuity, as the queries are not simply discarded – they return a subset of the requested data, so false positives don’t cause the application to hang or crash.
- Connection-Pooled User Identification: One of the problems with connection pooling, whereby an application using a single shared database connection for all users, is loss of the ability to track which actions are taken by which users at the database level. Connection pooling is common and essential for application development, but if all queries originate from the same account that makes granular security monitoring difficult. This feature uses a variety of techniques to correlate every query back to an application user for better auditing at the database level.
- Database Discovery: Databases have a habit of popping up all over the place without administrators being aware. Everything from virtual copies of production databases showing up in test environments, to Microsoft Access databases embedded in applications. These databases are commonly not secured to any standard, often have default configurations, and provide targets of opportunity for attackers. Database discovery works by scanning networks looking for databases communicating on standard database ports. Discovery tools may snapshot all current databases or alert admins when new undocumented databases appear. In some cases they can automatically initiate a vulnerability scan.
- Content Discovery: As much as we like to think we know our databases, we don’t always know what’s inside them. DSP solutions offer content discovery features to identify the use of things like Social Security numbers, even if they aren’t located where you expect. Discovery tools crawl through registered databases, looking for content and metadata that match policies, and generate alerts for sensitive content in unapproved locations. For example, you could create a policy to identify credit card numbers in any database and generate a report for PCI compliance. The tools can run on a scheduled basis so you can perform ongoing assessments, rather than combing through everything by hand every time an auditor comes knocking. Most start with a scan of column and table metadata, then follow with an analysis of the first n rows of each table, rather than trying to scan everything.
- Dynamic Content Analysis: Some tools allow you to act on the discovery results. Instead of manually identifying every field with Social Security numbers and building a different protection policy for each location, you create a single policy that alerts every time an administrator runs a
SELECTquery on any field discovered to contain one or more SSNs. As systems grow and change over time, the discovery continually identifies fields containing protected content and automatically applies the policy. We are also seeing DSP tools that monitor the results of live queries for sensitive data. Policies are then freed from being tied to specific fields, and can generate alerts or perform enforcement actions based on the result set. For example, a policy could generate an alert any time a query result contains a credit card number, no matter what columns were referenced in the query.
Next we will discuss administration and policy management for DSP.