CWE 798

Use of Hard-coded Credentials

Weakness ID: 798 (Weakness Base)

Status: Incomplete

Description

Description Summary

The software contains hard-coded credentials, such as a password or cryptographic key, which it uses for its own inbound authentication, outbound communication to external components, or encryption of internal data.

Extended Description

A hard-coded password typically leads to a significant authentication failure that can be difficult for the system administrator to detect. Once detected, it can be difficult to fix, so the administrator may be forced into disabling the product entirely. There are two main variations:

Inbound: the software contains an authentication mechanism that checks for a hard-coded password.

Outbound: the software connects to another system or component, and it contains hard-coded password for connecting to that component.

In the Inbound variant, a default administration account is created, and a simple password is hard-coded into the product and associated with that account. This hard-coded password is the same for each installation of the product, and it usually cannot be changed or disabled by system administrators without manually modifying the program, or otherwise patching the software. If the password is ever discovered or published (a common occurrence on the Internet), then anybody with knowledge of this password can access the product. Finally, since all installations of the software will have the same password, even across different organizations, this enables massive attacks such as worms to take place.

The Outbound variant applies to front-end systems that authenticate with a back-end service. The back-end service may require a fixed password which can be easily discovered. The programmer may simply hard-code those back-end credentials into the front-end software. Any user of that program may be able to extract the password. Client-side systems with hard-coded passwords pose even more of a threat, since the extraction of a password from a binary is usually very simple.

Time of Introduction

Architecture and Design

Applicable Platforms

Languages

Language-independent

Common Consequences

Scope	Effect
Authentication	If hard-coded passwords are used, it is almost certain that malicious users will gain access to the account in question.
Integrity Access Control	This weakness can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with sensitive information or even execute arbitrary code.

Likelihood of Exploit

Very High

Detection Methods

Black Box

Credential storage in configuration files is findable using black box methods, but the use of hard-coded credentials for an incoming authentication routine typically involves an account that is not visible outside of the code.

Effectiveness: Moderate

Automated Static Analysis

Automated white box techniques have been published for detecting hard-coded credentials for incoming authentication, but there is some expert disagreement regarding their effectiveness and applicability to a broad range of methods.

Manual Static Analysis

This weakness may be detectable using manual code analysis. Unless authentication is decentralized and applied throughout the software, there can be sufficient time for the analyst to find incoming authentication routines and examine the program logic looking for usage of hard-coded credentials. Configuration files could also be analyzed.

These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Manual Dynamic Analysis

For hard-coded credentials in incoming authentication: use monitoring tools that examine the software's process as it interacts with the operating system and the network. This technique is useful in cases when source code is unavailable, if the software was not developed by you, or if you want to verify that the build phase did not introduce any new weaknesses. Examples include debuggers that directly attach to the running process; system-call tracing utilities such as truss (Solaris) and strace (Linux); system activity monitors such as FileMon, RegMon, Process Monitor, and other Sysinternals utilities (Windows); and sniffers and protocol analyzers that monitor network traffic.

Attach the monitor to the process and perform a login. Using call trees or similar artifacts from the output, examine the associated behaviors and see if any of them appear to be comparing the input to a fixed string or value.

Demonstrative Examples

Example 1

The following code uses a hard-coded password to connect to a database:

(Bad Code)

Example Language: Java

...

DriverManager.getConnection(url, "scott", "tiger");

...

This is an example of an external hard-coded password on the client-side of a connection. This code will run successfully, but anyone who has access to it will have access to the password. Once the program has shipped, there is no going back from the database user "scott" with a password of "tiger" unless the program is patched. A devious employee with access to this information can use it to break into the system. Even worse, if attackers have access to the bytecode for application, they can use the javap -c command to access the disassembled code, which will contain the values of the passwords used. The result of this operation might look something like the following for the example above:

(Attack)

javap -c ConnMngr.class

22: ldc #36; //String jdbc:mysql://ixne.com/rxsql

24: ldc #38; //String scott

26: ldc #17; //String tiger

Example 2

The following code is an example of an internal hard-coded password in the back-end:

(Bad Code)

Example Languages: C and C++

int VerifyAdmin(char *password) {

if (strcmp(password, "Mew!")) {

printf("Incorrect Password!\n");

return(0)

}

printf("Entering Diagnostic Mode...\n");

return(1);

}

(Bad Code)

Example Language: Java

int VerifyAdmin(String password) {

if (passwd.Equals("Mew!")) {

return(0)

}

//Diagnostic Mode

return(1);

}

Every instance of this program can be placed into diagnostic mode with the same password. Even worse is the fact that if this program is distributed as a binary-only distribution, it is very difficult to change that password or disable this "functionality."

Potential Mitigations