Searching for Code in J2EE/Java

Input and Output Streams
These are used to read data into one’s application. They may be potential entry points into an application. The entry points may be from an external source and must be investigated. These may also be used in path traversal attacks or DoS attacks.

Java.io java.util.zip java.util.jar FileInputStream ObjectInputStream FilterInputStream PipedInputStream SequenceInputStream StringBufferInputStream BufferedReader ByteArrayInputStream CharArrayReader File ObjectInputStream PipedInputStream StreamTokenizer getResourceAsStream java.io.FileReader java.io.FileWriter java.io.RandomAccessFile java.io.File java.io.FileOutputStream mkdir renameTo java.io.File.delete java.io.File.listFiles java.io.File.list

Servlets
These API calls may be avenues for parameter, header, URL, and cookie tampering, HTTP Response Splitting and information leakage. They should be examined closely as many of such APIs obtain the parameters directly from HTTP requests.

javax.servlet.* getParameterNames getParameterValues getParameter getParameterMap getScheme getProtocol getContentType getServerName getRemoteAddr getRemoteHost getRealPath getLocalName getAttribute getAttributeNames getLocalAddr getAuthType getRemoteUser getCookies isSecure HttpServletRequest getQueryString getHeaderNames getHeaders getPrincipal getUserPrincipal isUserInRole getInputStream getOutputStream getWriter addCookie addHeader setHeader setAttribute putValue javax.servlet.http.Cookie getName getPath getDomain getComment getMethod getPath getReader getRealPath getRequestURI getRequestURL getServerName getValue getValueNames getRequestedSessionId

Cross Site Scripting
javax.servlet.ServletOutputStream.print javax.servlet.jsp.JspWriter.print java.io.PrintWriter.print

Response Splitting
javax.servlet.http.HttpServletResponse.sendRedirect addHeader, setHeader

Redirection
sendRedirect setStatus addHeader, setHeader

SQL & Database
Searching for Java Database related code this list should help you pinpoint classes/methods which are involved in the persistence layer of the application being reviewed.

jdbc executeQuery select insert update delete execute executestatement createStatement java.sql.ResultSet.getString java.sql.ResultSet.getObject java.sql.Statement.executeUpdate java.sql.Statement.executeQuery java.sql.Statement.execute java.sql.Statement.addBatch java.sql.Connection.prepareStatement java.sql.Connection.prepareCall

SSL
Looking for code which utilises SSL as a medium for point to point encryption. The following fragments should indicate where SSL functionality has been developed.

com.sun.net.ssl SSLContext SSLSocketFactory TrustManagerFactory HttpsURLConnection KeyManagerFactory

Session Management
getSession invalidate getId

Legacy Interaction
Here we may be vulnerable to command injection attacks or OS injection attacks. Java linking to the native OS can cause serious issues and potentially give rise to total server compromise.

java.lang.Runtime.exec java.lang.Runtime.getRuntime

Logging
We may come across some information leakage by examining code below contained in one’s application.

java.io.PrintStream.write log4j jLo Lumberjack MonoLog qflog just4log log4Ant JDLabAgent

Architectural Analysis
If we can identify major architectural components within that application (right away) it can help narrow our search, and we can then look for known vulnerabilities in those components and frameworks:

XMLHTTP
 * 1) Ajax

org.apache.struts
 * 1) Struts

org.springframework
 * 1) Spring

import javax.faces
 * 1) Java Server Faces (JSF)

import org.hibernate
 * 1) Hibernate

org.exolab.castor
 * 1) Castor

javax.xml
 * 1) JAXB

JMS
 * 1) JMS

Generic Keywords
Developers say the darnedest things in their source code. Look for the following keywords as pointers to possible software vulnerabilities:

Hack Kludge Bypass Steal Stolen Divert Broke Trick FIXME ToDo Password Backdoor

WEB 2.0
Ajax and JavaScript

Look for Ajax usage, and possible JavaScript issues:

document.write eval document.cookie window.location document.URL

XMLHTTP
window.createRequest