Common Weakness Enumeration

A Community-Developed List of Software Weakness Types

CWE/SANS Top 25 Most Dangerous Software Errors
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CWE-799: Improper Control of Interaction Frequency

Weakness ID: 799
Abstraction: Class
Status: Incomplete
Presentation Filter:
+ Description

Description Summary

The software does not properly limit the number or frequency of interactions that it has with an actor, such as the number of incoming requests.

Extended Description

This can allow the actor to perform actions more frequently than expected. The actor could be a human or an automated process such as a virus or bot. This could be used to cause a denial of service, compromise program logic (such as limiting humans to a single vote), or other consequences. For example, an authentication routine might not limit the number of times an attacker can guess a password. Or, a web site might conduct a poll but only expect humans to vote a maximum of once a day.

+ Alternate Terms
Insufficient anti-automation:

The term "insufficient anti-automation" focuses primarly on non-human actors such as viruses or bots, but the scope of this CWE entry is broader.

Brute force:

Vulnerabilities that can be targeted using brute force attacks are often symptomatic of this weakness.

+ Time of Introduction
  • Architecture and Design
  • Implementation
  • Operation
+ Applicable Platforms



+ Common Consequences
Access Control

Technical Impact: DoS: resource consumption (other); Bypass protection mechanism; Other

+ Demonstrative Examples

Example 1

In the following code a username and password is read from a socket and an attempt is made to authenticate the username and password. The code will continuously checked the socket for a username and password until it has been authenticated.

(Bad Code)
Example Languages: C and C++ 
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);

This code does not place any restriction on the number of authentication attempts made. There should be a limit on 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 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);
if (isValidUser) {
else {
+ Observed Examples
Mail server allows attackers to prevent other users from accessing mail by sending large number of rapid requests.
+ Weakness Ordinalities
(where the weakness exists independent of other weaknesses)
+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfCategoryCategory438Behavioral Problems
Development Concepts (primary)699
ChildOfWeakness ClassWeakness Class691Insufficient Control Flow Management
Research Concepts (primary)1000
ChildOfCategoryCategory8082010 Top 25 - Weaknesses On the Cusp
Weaknesses in the 2010 CWE/SANS Top 25 Most Dangerous Programming Errors (primary)800
ChildOfCategoryCategory840Business Logic Errors
Development Concepts699
ParentOfWeakness BaseWeakness Base307Improper Restriction of Excessive Authentication Attempts
Research Concepts1000
ParentOfWeakness BaseWeakness Base837Improper Enforcement of a Single, Unique Action
Development Concepts (primary)699
Research Concepts (primary)1000
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
WASC21Insufficient Anti-Automation
+ References
Web Application Security Consortium. "Insufficient Anti-automation". <>.
+ Content History
Submission DateSubmitterOrganizationSource
2010-01-15MITREInternal CWE Team
New entry to handle anti-automation as identified in WASC.
Modification DateModifierOrganizationSource
2010-04-05CWE Content TeamMITREInternal
updated Demonstrative_Examples
2011-03-29CWE Content TeamMITREInternal
updated Observed_Examples, Relationships
2011-06-01CWE Content TeamMITREInternal
updated Common_Consequences

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Page Last Updated: May 05, 2017