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Wiki MarkupHardcoding sensitive Hard coding sensitive information, such as passwords, server IP addresses, and encryption keys can expose the information to attackers. Anyone who has access to the class files can decompile them and discover the sensitive information. Leaking data protected by International Traffic in Arms Regulations (ITAR) or the Health Insurance Portability and Accountability Act (HIPAA) can also have legal consequences. Consequently, programs must not hard code sensitive information.

Hard coding sensitive information also increases the need to manage and accommodate changes to the code. For example, changing a hard-coded password in a deployed program may require distribution of a patch [Chess 2007]., is an extremely dangerous practice. This is because adversaries who have access to the class files can decompile them to discover the sensitive information. Additionally, once the system goes into production mode, it can become unwieldy to manage and accommodate changes to the code. For instance, a change in password may need to be communicated using a patch \[[Chess 07|AA. Java References#Chess 07]\].

Noncompliant Code Example

This noncompliant code example uses a password field instantiated as a String. includes a hard-coded server IP address in a constant String:

class HardcodedIPaddress {
  String passwordipAddress = new String("guest172.16.254.1");
  public static void main(String[] args) {
    //...
  }
}

A malicious user can use the javap -c HardcodedIPaddress command to disassemble the class and discover the hardcoded passwordhard-coded server IP address. The output of the disassembler as shown below, reveals the password guest in cleartext.server IP address 172.16.254.1 in clear text:

Compiled from "HardcodedIPaddress.java"
class HardcodedIPaddress extends java.lang.Object{
java.lang.String passwordipAddress;

HardcodedIPaddress();
  Code:
   0:	     aload_0
   1:	invokespecial	     invokespecial     #1; //Method java/lang/Object."<init>":()V
   4:	     aload_0
   5:	new	     new   #2; //class java/lang/String
   8:	     dup
   9:	ldc	     ldc   #3; //String guest172.16.254.1
   11:	invokespecial	    invokespecial     #4; //Method java/lang/String."<init>":(Ljava/lang/String;)V
   14:	putfield	    putfield    #5; //Field passwordipAddress:Ljava/lang/String;
   17:	    return

public static void main(java.lang.String[]);
  Code:
   0:	     return

}

Compliant Solution

This compliant solution uses a char array to store the password after it is retrieved retrieves the server IP address from an external file existing located in a secured directory. The password is immediately cleared out after use. This limits the exposure timesecure directory, as recommended by FIO00-J. Do not operate on files in shared directories. It reads the file in compliance with FIO10-J. Ensure the array is filled when using read() to fill an array. Exposure of the IP address is further limited by storing it in a char array rather than a java.lang.String, and by clearing the server IP address from memory immediately after use.

class PasswordIPaddress {
  public static void main(String[] args) throws IOException {
    char[] passwordipAddress = new char[100];	;
    int offset = 0;
    int charsRead = 0;
    BufferedReader br = null;
    try {
      br = new BufferedReader(new InputStreamReader(
             new FileInputStream("passwordserveripaddress.txt")));
      while ((charsRead = br.read(ipAddress, offset, ipAddress.length - offset))
       //  Reads the password into the char array, returns the number of bytes read 
!= -1) {
        offset += charsRead;
        intif n(offset >= bripAddress.read(password);  length) {
          break;
    // Decrypt password, perform operations}
      for(int}
 i = n - 1; i
 >= 0; i--) {  // Manually clear out the password immediately after use 
 ... Work with IP address

    } finally {
       password[i] = 0;	 
    }
Arrays.fill(ipAddress,  (byte) 0);
      br.close();
    }
  }
}

To further limit the exposure time of the sensitive password, follow the guideline MSC08-J. Limit the lifetime of sensitive data by replacing server IP address, replace BufferedReader with a direct native input/output (NIO) buffer, which can be cleared immediately after use.

Noncompliant Code Example

...

(Hard-Coded Database Password)

The This noncompliant code example hardcodes the user name and password fields in the SQL connection request .are hard coded in this noncompliant code example:

public final Connection getConnection() throws SQLException {
  return DriverManager.getConnection(
      "jdbc:mysql://localhost/dbName", 
      "username", "password");
}

Note that the one- and two-argument java.sql.DriverManager.getConnection() methods may can also be used incorrectly. Applets that contain similar code are also noncompliant because they may be executed in untrusted environments.

Compliant Solution

This compliant solution reads the user name and password from a configuration file present located in a secure directory. :

public final Connection getConnection() throws SQLException {
  String username;
  String password;
  // Username and password are read at runtime from a secure config file
public final Connectionreturn DriverManager.getConnection()
 throws SQLException {
  return DriverManager.getConnection("jdbc:mysql://localhost/dbName", username, password);
}

It is also permissible to prompt the user for the user name and password at runtime and use the entered values.

When possible, sensitive information such as passwords should be stored in character arrays rather than strings because the Java Virtual Machine may retain strings long after they are no longer needed. However, this example uses strings because DriverManager.getConnection() requires them.

Risk Assessment

Hardcoding sensitive information allows a malicious user to glean the information.Hard coding sensitive information exposes that information to attackers. The severity of this rule can vary depending on the kind of information that is disclosed. Frequently, the information disclosed is password or key information, which can lead to remote exploitation. Consequently, a high severity rating is given but may be adjusted downwards according to the nature of the sensitive data. 

Automated Detection

...

Tool	Version	Checker	Description
CodeSonar	Include Page CodeSonar_V CodeSonar_V	JAVA.HARDCODED.PASSWD JAVA.MISC.SD.EXT	Hardcoded Password (Java) Sensitive Data Written to External Storage (Java)
Coverity	7.5	HARDCODED_CREDENTIALS CONFIG FB.DMI_CONSTANT_DB_ PASSWORD FB.DMI_EMPTY_DB_PASSWORD	Implemented
Fortify	1.0	Password_Management Password_Management__Hardcoded_Password	Partially implemented
Parasoft Jtest	Include Page Parasoft_V Parasoft_V	CERT.MSC03.HCCS CERT.MSC03.HCCK CERT.MSC03.AHCA	Avoid passing hardcoded usernames/passwords/URLs to database connection methods Avoid using hard-coded cryptographic keys Avoid hard-coding the arguments to certain methods
PMD	1.0	AvoidUsingHardCodedIP	Partially implemented
SonarQube	Include Page SonarQube_V SonarQube_V	S1313 S2068	Partially implemented

Related Vulnerabilities

GERONIMO-2925

Other Languages

...

 describes a vulnerability in the WAS CE tool, which is based on Apache Geronimo. It uses the Advanced Encryption Standard (AES) to encrypt passwords but uses a hard-coded key that is identical for all the WAS CE server instances. Consequently, anyone who can download the software is provided with the key to every instance of the tool. This vulnerability was resolved by having each new installation of the tool generate its own unique key and use it from that time on.

Related Guidelines

...

Android Implementation Details

Hard-coded information can be easily obtained on Android by using the apktool to decompile an application or by using dex2jar to convert a dex file to a jar file.

Bibliography

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References

\[[Gong 03|AA. Java References#Gong 03]\] 9.4 Private Object State and Object Immutability
\[[Chess 07|AA. Java References#Chess 07]\] 11.2 Outbound Passwords: Keep Passwords out of Source Code
\[[Fortify 08|AA. Java References#Fortify 08]\] "Unsafe Mobile Code: Database Access"
\[[MITRE 09|AA. Java References#MITRE 09]\] [CWE ID 259|http://cwe.mitre.org/data/definitions/259.html] "Hard-Coded Password"

MSC30-J. Generate truly random numbers      49. Miscellaneous (MSC)      MSC32-J. Make sensitive classes noncloneable