Improper Restriction of Excessive Authentication Attempts
Weakness ID: 307 (Weakness Base)Status: Draft
+ Description

Description Summary

The software does not implement sufficient measures to prevent multiple failed authentication attempts within in a short time frame, making it more susceptible to brute force attacks.
+ Time of Introduction
  • Architecture and Design
+ Applicable Platforms

Languages

Language-independent

+ Demonstrative Examples

Example 1

The following code, extracted from a servlet's doPost() method, performs an authentication lookup every time the servlet is invoked and makes no attempt to restrict excessive authentication attempts.

(Bad Code)
Example Language: Java 
String username = request.getParameter("username");
String password = request.getParameter("password");

int authResult = authenticateUser(username, password);

Example 2

In January 2009, an attacker was able to gain administrator access to a Twitter server because the server did not restrict the number of login attempts. The attacker targeted a member of Twitter's support team and was able to successfully guess the member's password using a brute force with a large number of common words. Once the attacker gained access as the member of the support staff, he used the administrator panel to gain access to 33 accounts that belonged to celebrities and politicians. Ultimately, fake Twitter messages were sent that appeared to come from the compromised accounts.

Example 2 References:

Kim Zetter. "Weak Password Brings ‘Happiness’ to Twitter Hacker". 2009-01-09. <http://www.wired.com/threatlevel/2009/01/professed-twitt/>.

Example 3

In the following C/C++ example the validateUser method opens a socket connection, reads a username and password from the socket and attempts to authenticate the username and password.

(Bad Code)
Example Languages: C and C++ 
int validateUser(char *host, int port)
{
int socket = openSocketConnection(host, port);
if (socket < 0) {
printf("Unable to open socket connection");
return(FAIL);
}

int isValidUser = 0;
char username[USERNAME_SIZE];
char password[PASSWORD_SIZE];

while (isValidUser == 0) {
if (getNextMessage(socket, username, USERNAME_SIZE) > 0) {
if (getNextMessage(socket, password, PASSWORD_SIZE) > 0) {
isValidUser = AuthenticateUser(username, password);
}
}
}
return(SUCCESS);
}

The validateUser method will continuously check for a valid username and password without any restriction on the number of authentication attempts made. The method should limit the number of authentication attempts made to prevent brute force attacks as in the following example code.

(Good Code)
Example Languages: C and C++ 
int validateUser(char *host, int port)
{
...

int count = 0;
while ((isValidUser == 0) && (count < MAX_ATTEMPTS)) {
if (getNextMessage(socket, username, USERNAME_SIZE) > 0) {
if (getNextMessage(socket, password, PASSWORD_SIZE) > 0) {
isValidUser = AuthenticateUser(username, password);
}
}
count++;
}
if (isValidUser) {
return(SUCCESS);
}
else {
return(FAIL);
}
}
+ Observed Examples
ReferenceDescription
CVE-1999-1152Product does not disconnect or timeout after multiple failed logins.
CVE-2001-1291Product does not disconnect or timeout after multiple failed logins.
CVE-2001-0395Product does not disconnect or timeout after multiple failed logins.
CVE-2001-1339Product does not disconnect or timeout after multiple failed logins.
CVE-2002-0628Product does not disconnect or timeout after multiple failed logins.
CVE-1999-1324User accounts not disabled when they exceed a threshold; possibly a resultant problem.
+ Potential Mitigations

Phase: Architecture and Design

Common protection mechanisms include:

  • Disconnecting the user after a small number of failed attempts

  • Implementing a timeout

  • Locking out a targeted account

  • Requiring a computational task on the user's part.

Phase: Architecture and Design

Strategy: Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness ClassWeakness Class287Improper Authentication
Development Concepts (primary)699
Research Concepts (primary)1000
ChildOfCategoryCategory724OWASP Top Ten 2004 Category A3 - Broken Authentication and Session Management
Weaknesses in OWASP Top Ten (2004) (primary)711
ChildOfWeakness ClassWeakness Class799Improper Control of Interaction Frequency
Research Concepts1000
ChildOfCategoryCategory8082010 Top 25 - Weaknesses On the Cusp
Weaknesses in the 2010 CWE/SANS Top 25 Most Dangerous Programming Errors (primary)800
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERAUTHENT.MULTFAILMultiple Failed Authentication Attempts not Prevented
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVERExternally Mined
Modifications
Modification DateModifierOrganizationSource
2008-07-01Sean EidemillerCigitalExternal
added/updated demonstrative examples
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Taxonomy Mappings
2009-03-10CWE Content TeamMITREInternal
updated Relationships
2009-07-27CWE Content TeamMITREInternal
updated Observed Examples
2009-12-28CWE Content TeamMITREInternal
updated Applicable Platforms, Demonstrative Examples, Potential Mitigations
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Multiple Failed Authentication Attempts not Prevented
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