Page History

...

It is important to not that for expressions such as regular expressions and SQL sequences, where a particular wild card is of the form '\X', the java String representation would be:

"\\X"

Noncompliant Code Example

In the following example, a method performing matching to regular expressions, matchPattern, is implemented. However, the assumption is that the pattern matches to word boundaries and will thus split a given string into individual words.

...

The String WORDS is compiled to the backspace character instead of the regular expression for splitting on word boundaries.

Compliant Solution

This compliant solution shows the correct value of the String WORDS to produce a regular expression to split on word boundaries.

...

In this example, the String WORDS is compiled to "\b", the pattern for matching to word boundaries. This is because the escape on the slash is converted to a single slash when the String is compiled.

Risk Assessment

Incorrect usage of escape characters in Strings for statements involving Pattern, SQL, XML, and other systems that take Strings could result in misinterpretation of and potentially corruption of data.

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this rule on the CERT website.

References

\[[API 06|AA. Java References#API 06]\] [Class Pattern|http://java.sun.com/javase/6/docs/api/java/util/regex/Pattern.html]
\[[API 06|AA. Java References#API 06]\] [Package java.sql|http://java.sun.com/javase/6/docs/api/java/sql/package-summary.html]
\[[MSDN 09|AA. Java References#MSDN 09]\] [Using SQL Escape Sequences|http://msdn.microsoft.com/en-us/library/ms378045(SQL.90).aspx]