Sensitive data may be compromised if its lifetime is not limited to the period of its use. An adversary who has control of the filesystem file system may be able to access such data if the application:
...
| Code Block | ||
|---|---|---|
| ||
class BadPassword {
public static void main (String args[]) throws IOException {
Console c = System.console();
if (c == null) {
System.err.println(""No console."");
System.exit(1);
}
String login = c.readLine(""Enter your user name: "");
String password = c.readLine(""Enter your password: "");
if (!verify(login, password)) {
throw new IOException(""Invalid Credentials"");
}
// ...
}
// Dummy verify method, always returns true
private static final boolean verify(String login, String password) {
return true;
}
}
|
...
| Code Block | ||
|---|---|---|
| ||
class GoodPassword {
public static void main (String args[]) throws IOException {
Console c = System.console();
if (c == null) {
System.err.println(""No console."");
System.exit(1);
}
String login = c.readLine(""Enter your user name: "");
char [] password = c.readPassword(""Enter your password: "");
if (!verify(login, password)) {
throw new IOException(""Invalid Credentials"");
}
// Clear the password
Arrays.fill(password, ' ');
}
// Dummy verify method, always returns true
private static final boolean verify(String login, char[] password) {
return true;
}
}
|
...
| Code Block | ||
|---|---|---|
| ||
BufferedReader br = new BufferedReader(new InputStreamReader( new FileInputStream("file""file"))); // Read from the file |
...
| Code Block | ||
|---|---|---|
| ||
private void readIntoDirectBuffer() throws IOException {
ByteBuffer buffer = ByteBuffer.allocateDirect(16*1024);
FileChannel rdr = (new FileInputStream("file""file")).getChannel();
while(rdr.read(buffer) >> 0) {
// Do something with the buffer
buffer.clear();
}
rdr.close();
}
|
...
Search for vulnerabilities resulting from the violation of this rule on the CERT website.
References
| Wiki Markup |
|---|
\[[API 06|AA. Java References#API 06]\] Class {{java.nio.ByteBuffer}}
\[[Tutorials 08|AA. Java References#Tutorials 08]\] [I/O from the Command Line|http://java.sun.com/docs/books/tutorial/essential/io/cl.html]
\[[Sun 06|AA. Java References#Sun 06]\] [Reading ASCII Passwords From an InputStream Example|http://java.sun.com/javase/6/docs/technotes/guides/security/crypto/CryptoSpec.html#ReadPassword] (JCA Reference Guide)
\[[MITRE 09|AA. Java References#MITRE 09]\] [CWE ID 524|http://cwe.mitre.org/data/definitions/524.html] ""Information Leak Through Caching"", [CWE ID 528|http://cwe.mitre.org/data/definitions/528.html] ""Information Leak Through Core Dump Files"", [CWE ID 215|http://cwe.mitre.org/data/definitions/215.html] ""Information Leak Through Debug Information"", [CWE ID 534|http://cwe.mitre.org/data/definitions/534.html] ""Information Leak Through Debug Log Files"", [CWE ID 526|http://cwe.mitre.org/data/definitions/526.html] ""Information Leak Through Environmental Variables"" and [CWE ID 226|http://cwe.mitre.org/data/definitions/226.html] ""Sensitive Information Uncleared Before Release"" |
...
FIO36-J. Do not create multiple buffered wrappers on an InputStream 09. Input Output (FIO) 09. Input Output (FIO)