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
Hard-coded credentials typically create a significant hole that allows an attacker to bypass the authentication that has been configured by the software administrator. This hole might be difficult for the system administrator to detect. Even if 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 the input credentials against a hard-coded set of credentials.
Outbound: the software connects to another system or component, and it contains hard-coded credentials 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
Architectural Paradigms
Mobile Application
Common Consequences
Scope
Effect
Access Control
Technical Impact: Bypass protection
mechanism
If hard-coded passwords are used, it is almost certain that malicious
users will gain access to the account in question.
Integrity
Confidentiality
Availability
Access Control
Other
Technical Impact: Read application
data; Gain privileges / assume
identity; Execute unauthorized code or
commands; Other
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:
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."
Example 3
The following code examples attempt to verify a password using a
hard-coded cryptographic key. The cryptographic key is within a hard-coded
string value that is compared to the password and a true or false value is
returned for verification that the password is equivalent to the hard-coded
cryptographic key.
(Bad Code)
Example Languages: C and C++
int VerifyAdmin(char *password) {
if (strcmp(password,"68af404b513073584c4b6f22b6c63e6b"))
{
printf("Incorrect Password!\n");
return(0);
}
printf("Entering Diagnostic Mode...\n");
return(1);
}
(Bad Code)
Example
Language: Java
public boolean VerifyAdmin(String password) {
if (password.equals("68af404b513073584c4b6f22b6c63e6b"))
{
if (password.Equals("68af404b513073584c4b6f22b6c63e6b"))
{
Console.WriteLine("Entering Diagnostic Mode...");
return(1);
}
Console.WriteLine("Incorrect Password!");
return(0);
}
Example 4
The following examples show a portion of properties and
configuration files for Java and ASP.NET applications. The files include
username and password information but they are stored in
plaintext.
This Java example shows a properties file with a plaintext username /
password pair.
(Bad Code)
Example
Language: Java
# Java Web App ResourceBundle properties file
...
webapp.ldap.username=secretUsername
webapp.ldap.password=secretPassword
...
The following example shows a portion of a configuration file for an
ASP.Net application. This configuration file includes username and
password information for a connection to a database but the pair is
stored in plaintext.
Username and password information should not be included in a configuration file or a properties file in plaintext as this will allow anyone who can read the file access to the resource. If possible, encrypt this information and avoid CWE-260 and CWE-13.
VoIP product uses hard coded public and private
SNMP community strings that cannot be changed, which allows remote attackers
to obtain sensitive information
Backup product contains hard-coded credentials
that effectively serve as a back door, which allows remote attackers to
access the file system
Potential Mitigations
Phase: Architecture and Design
For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible [R.798.1].
In Windows environments, the Encrypted File System (EFS) may provide
some protection.
Phase: Architecture and Design
For inbound authentication: Rather than hard-code a default username
and password, key, or other authentication credentials for first time
logins, utilize a "first login" mode that requires the user to enter a
unique strong password or key.
Phase: Architecture and Design
If the software must contain hard-coded credentials or they cannot be
removed, perform access control checks and limit which entities can
access the feature that requires the hard-coded credentials. For
example, a feature might only be enabled through the system console
instead of through a network connection.
Phase: Architecture and Design
For inbound authentication using passwords: apply strong one-way
hashes to passwords and store those hashes in a configuration file or
database with appropriate access control. That way, theft of the
file/database still requires the attacker to try to crack the password.
When handling an incoming password during authentication, take the hash
of the password and compare it to the saved hash.
Use randomly assigned salts for each separate hash that is generated.
This increases the amount of computation that an attacker needs to
conduct a brute-force attack, possibly limiting the effectiveness of the
rainbow table method.
Phase: Architecture and Design
For front-end to back-end connections: Three solutions are possible,
although none are complete.
The first suggestion involves the use of generated passwords or
keys that are changed automatically and must be entered at given
time intervals by a system administrator. These passwords will be
held in memory and only be valid for the time intervals.
Next, the passwords or keys should be limited at the back end to
only performing actions valid for the front end, as opposed to
having full access.
Finally, the messages sent should be tagged and checksummed with
time sensitive values so as to prevent replay-style attacks.
Weakness Ordinalities
Ordinality
Description
Primary
(where
the weakness exists independent of other weaknesses)