Tag: security

Questions Related to security

try { 
    //code to do  IO operations 
    return var1; 
} Catch(Exception e) { 
    return var2; 
} finally{ 
    return var3; 
}

From security view point problem with above code is
technology security

  1. It is returning a value in finally block

  2. It is catching Exception

  3. Both a & b

  4. Nothing is wrong

Show answer
Correct Option: C 
public void dummyFunction(String var1,String var2){ 
    try{ 
        Connection con=getConnection(); 
        String query=”select * from table1 where col1=”+var1 +”and col2=”+var2; 
        Statement st=conn.createStatement(); 
        ResultSet rs=st.executeQuery(query); 
        …… ….. 
    } catch(Exception e) { } 

}

var1 and var2 are inputs from user directly passed to this functions. This code is
technology security

  1. Vulnerable to SQL Injection

  2. Vulnerable to DoS

  3. Both a & b

  4. None of the above

Show answer
Correct Option: C

Below function is used to read file from a directory on the filesystem. This code runs with read only OS level privilege on this directory. fileName is parameter from user directly passed to this function

public void dummyFunction(String fileName){             
    FileInputStream fis = new FileInputStream(fileName); // code to read file content only, no write modify or delete 
}
technology security

  1. Security is handled at OS level by giving only read level privilege so no need to put an extra check here.

  2. Only problem here is that fileName may not be syntactically incorrect so it should be validated before using it in the function.

  3. This code can lead to information disclosure attack

  4. Java provides enough security by default for IO operations so this code is not vulnerable.

Show answer
Correct Option: C

Please select which of the following statements are NOT true regarding the AccessController class?
technology security

  1. Can be used to mark code as being "privileged", thus affecting subsequent access determinations

  2. Can be to decide whether an access to a critical system resource is to be allowed or denied, based on the security policy currently in effect

  3. Can be used to obtain a "snapshot" of the current calling context

  4. Can be used to compute a cryptographically secure hash

Show answer
Correct Option: D

Which of the following best describes how to sign a document using a digital signature?
technology security

  1. Create a hash of the document and encrypt the resulting hash using the signer's private key

  2. Encrypt the document using the signer's private key

  3. Encrypt the document using the signer's private key and create a hash of the encrypted document

  4. Encrypt the document using the signer's public key

Show answer
Correct Option: A
Explanation:

To sign a document using a digital signature, the user needs to know the basic concepts of public key cryptography and digital signatures.

Now, let's go through each option and explain why it is right or wrong:

A. Create a hash of the document and encrypt the resulting hash using the signer's private key. This option is partially correct. To sign a document, the signer first creates a hash of the document to be signed. The hash is then encrypted using the signer's private key. However, the encrypted hash is not the signature itself; it is just one part of the signature. The encrypted hash, along with the signer's public key and other information, is used to create the digital signature.

B. Encrypt the document using the signer's private key. This option is incorrect. Signing a document does not involve encrypting the entire document using the signer's private key. Instead, the document is hashed and a digital signature is created using the private key.

C. Encrypt the document using the signer's private key and create a hash of the encrypted document. This option is incorrect. Signing a document does not involve encrypting the document using the signer's private key. Instead, the document is hashed and a digital signature is created using the private key.

D. Encrypt the document using the signer's public key. This option is incorrect. Signing a document does not involve encrypting the document using the signer's public key. Instead, the document is hashed and a digital signature is created using the signer's private key.

The Answer is: A

Data returned by which of the following methods should be validated before using it

  1. getParameter ()
  2. getQueryString ()
  3. getCookies ()
  4. getHeaders ()
technology security

  1. 1

  2. 1 and 2

  3. 1,2 and 3

  4. 1,2,3 and 4

Show answer
Correct Option: D

Which of the following are countermeasures for XSS

  1. Releasing Resources after use
  2. Input Validation
  3. Running with least privilege
  4. URL based access control
  5. Output Encoding
technology security

  1. 1 and 4

  2. 2 and 4

  3. 2 and 5

  4. 3 and 5

Show answer
Correct Option: C

The following code is part of a system daemon that is run with elevated privileges. It opens a temp file in /tmp directory as a cache. Is there an issue in this code sample? Please assume that filling up /tmp is not an issue here. 

int outfile = fopen(“/tmp/cache_data”, O_WRONLY | O_CREAT | O_TRUNC, 0600);
technology security

  1. Since the file name is hard coded, fopen() will fail if the file already exists.

  2. 0600 is not a secure option. The parameter 0600 should be changed to 0666

  3. Attackers can exploit by creating a symboling link /tmp/cache_data that points to a system file.

  4. Attackers can exploit the application's cache by writing directly to /tmp/cache_data

Show answer
Correct Option: C

Is writing to an already freed memory a vulnerability?

x = malloc(200); /* do something with x */ 
free (x); /* do something else */  
strcpy(x, “somedata”);
technology security

  1. Overwriting freed memory is a security vulnerability

  2. Depends on the application and how important “somedata” is

  3. This will result in a buffer overflow since the freed memory location cannot handle 8 characters of data “somedata”

  4. strcpy() will fail as it cannot write to already freed memory, and the application will crash.

Show answer
Correct Option: A

AI Explanation

To answer this question, let's go through each option:

Option A) Overwriting freed memory is a security vulnerability - This option is correct. Writing to an already freed memory is a security vulnerability. When memory is freed using the free() function, the operating system marks that memory as available for other allocations. If you try to write to that memory after it has been freed, it can lead to undefined behavior, including potential security vulnerabilities such as buffer overflows or information disclosure.

Option B) Depends on the application and how important "somedata" is - This option is not the correct answer. While the importance of "somedata" may impact the severity of the vulnerability, the act of writing to already freed memory itself is a security vulnerability.

Option C) This will result in a buffer overflow since the freed memory location cannot handle 8 characters of data "somedata" - This option is incorrect. A buffer overflow occurs when more data is written to a buffer than it can handle, exceeding its allocated size. In this case, the issue is not specifically a buffer overflow, but rather writing to already freed memory.

Option D) strcpy() will fail as it cannot write to already freed memory, and the application will crash - This option is incorrect. The behavior of writing to already freed memory is undefined. It might crash the application, or it might not. It is not guaranteed to fail or crash in all cases.

The correct answer is A) Overwriting freed memory is a security vulnerability. This option is correct because writing to already freed memory can lead to security vulnerabilities and should be avoided.

In the following code, which is the location of vulnerability? 

1  bIsAdmin = true; 
2  try  
3  { 
4  function (); 
5   bIsAdmin = isAdminUser(userName); 
6  } 
7  catch (Exception ex)  
8  { 
9   log.write(ex.toString()); 
10 }
technology security

  1. Line 9

  2. Line 5

  3. Line 7

  4. Line 1

Show answer
Correct Option: D