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cwe:cn:definition:798

CWE-798:使用硬编码的凭证

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

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.

Likelihood of Exploit

Very High

Common Consequences

Scope Technical Impace Note
Access_ControlBypass protection mechanismIf 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
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.

Detection Methods

Detection Method - 1

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.

Detection Method - 2

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.

Detection Method - 3

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.

Detection Method - 4

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.

Detection Method - 5

Automated Static Analysis - Binary / Bytecode

According to SOAR, the following detection techniques may be useful:

Detection Method - 6

Manual Static Analysis - Binary / Bytecode

According to SOAR, the following detection techniques may be useful:

Detection Method - 7

Dynamic Analysis with manual results interpretation

According to SOAR, the following detection techniques may be useful:

Detection Method - 8

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Detection Method - 9

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Detection Method - 10

Automated Static Analysis

According to SOAR, the following detection techniques may be useful:

Detection Method - 11

Architecture / Design Review

According to SOAR, the following detection techniques may be useful:

Potential Mitigations

Mitigation - 1

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.

Mitigation - 2

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.

Mitigation - 3

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.

Mitigation - 4

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.

Mitigation - 5

Architecture and Design

For front-end to back-end connections: Three solutions are possible, although none are complete.

Demonstrative Examples

Example - 1

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

... 
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:

javap -c ConnMngr.class 
22: ldc #36; //String jdbc:mysql://ixne.com/rxsql 
24: ldc #38; //String scott 
26: ldc #17; //String tiger 
 
2013/05/30 13:23

Example - 2

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

int VerifyAdmin(char *password) { 
if (strcmp(password, "Mew!")) { 
 
printf("Incorrect Password!\n"); 
return(0) 
 
} 
printf("Entering Diagnostic Mode...\n"); 
return(1); 
 
} 
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.”

2013/05/30 13:23

Example - 3

The following code examples attempt to verify a password using a hard-coded cryptographic key.

int VerifyAdmin(char *password) { 
if (strcmp(password,"68af404b513073584c4b6f22b6c63e6b")) { 
 
printf("Incorrect Password!\n"); 
return(0); 
 
} 
printf("Entering Diagnostic Mode...\n"); 
return(1); 
 
} 
public boolean VerifyAdmin(String password) { 
if (password.equals("68af404b513073584c4b6f22b6c63e6b")) { 
System.out.println("Entering Diagnostic Mode..."); 
return true; 
 
} 
System.out.println("Incorrect Password!"); 
return false; 
 
int VerifyAdmin(String password) { 
if (password.Equals("68af404b513073584c4b6f22b6c63e6b")) { 
Console.WriteLine("Entering Diagnostic Mode..."); 
return(1); 
 
} 
Console.WriteLine("Incorrect Password!"); 
return(0); 
 
} 

The cryptographic key is within a hard-coded string value that is compared to the password. It is likely that an attacker will be able to read the key and compromise the system.

2013/05/30 13:23

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.

# 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.

... 
<connectionStrings> 
<add name="ud_DEV" connectionString="connectDB=uDB; uid=db2admin; pwd=password; dbalias=uDB;" providerName="System.Data.Odbc" /> 
</connectionStrings> 
... 

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.

2013/05/30 13:23

Observed Examples

Reference Description
CVE-2010-2772SCADA system uses a hard-coded password to protect back-end database containing authorization information, exploited by Stuxnet worm
CVE-2010-2073FTP server library uses hard-coded usernames and passwords for three default accounts
CVE-2010-1573Chain: Router firmware uses hard-coded username and password for access to debug functionality, which can be used to execute arbitrary code
CVE-2008-2369Server uses hard-coded authentication key
CVE-2008-0961Backup product uses hard-coded username and password, allowing attackers to bypass authentication via the RPC interface
CVE-2008-1160Security appliance uses hard-coded password allowing attackers to gain root access
CVE-2006-7142Drive encryption product stores hard-coded cryptographic keys for encrypted configuration files in executable programs
CVE-2005-3716VoIP product uses unchangeable hard-coded public credentials that cannot be changed, which allows attackers to obtain sensitive information
CVE-2005-3803VoIP product uses hard coded public and private SNMP community strings that cannot be changed, which allows remote attackers to obtain sensitive information
CVE-2005-0496Backup product contains hard-coded credentials that effectively serve as a back door, which allows remote attackers to access the file system
cwe/cn/definition/798.txt · 最后更改: 2014/09/04 14:53 (外部编辑)