The software contains a hard-coded password, which it uses for its own inbound authentication or for outbound communication to external components.
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
Implementation
Architecture and Design
Applicable Platforms
Languages
Language-independent
Common Consequences
Scope
Effect
Access Control
Technical Impact: Gain privileges / assume
identity
If hard-coded passwords are used, it is almost certain that malicious
users will gain access through the account in question.
Likelihood of Exploit
Very High
Detection Methods
Manual Analysis
This weakness can be detected using tools and techniques that require
manual (human) analysis, such as penetration testing, threat modeling,
and interactive tools that allow the tester to record and modify an
active session.
These may be more effective than strictly automated techniques. This
is especially the case with weaknesses that are related to design and
business rules.
Black Box
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
disassembled code, look at the associated instructions 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."
Potential Mitigations
Phase: Architecture and Design
For outbound authentication: store passwords 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.
Phase: Architecture and Design
For inbound authentication: Rather than hard-code a default username
and password for first time logins, utilize a "first login" mode that
requires the user to enter a unique strong password.
Phase: Architecture and Design
Perform access control checks and limit which entities can access the
feature that requires the hard-coded password. 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: apply strong one-way hashes to your
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 receiving
an incoming password during authentication, take the hash of the
password and compare it to the hash that you have saved.
Use randomly assigned salts for each separate hash that you generate.
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 which
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 used 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)
Lifting credential(s)/key material embedded in client distributions (thick or thin)
White Box Definitions
Definition: A weakness where code path has:
1. end statement that passes a data item to a password function
2. value of the data item is a constant
References
[REF-17] Michael Howard, David LeBlanc
and John Viega. "24 Deadly Sins of Software Security". "Sin 19: Use of Weak Password-Based Systems." Page
279. McGraw-Hill. 2010.
Maintenance Notes
This entry should probably be split into multiple variants: an inbound
variant (as seen in the second demonstrative example) and an outbound
variant (as seen in the first demonstrative example). These variants are
likely to have different consequences, detectability, etc. See extended
description.
Description
