CWE-799: Improper Control of Interaction Frequency

Description

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

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.

Potential Impact

Availability, Access Control, Other

DoS: Resource Consumption (Other), Bypass Protection Mechanism, Other

Demonstrative Examples

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

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);

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

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);}

Real-World CVE Examples

CVE ID	Description
CVE-2024-50653	Chain: e-commerce product has a "front-end restriction" for coupon use (CWE-602), but the server does not restrict the number of requests for the same coupon (CWE-799)
CVE-2002-1876	Mail server allows attackers to prevent other users from accessing mail by sending large number of rapid requests.

Taxonomy Mappings

WASC: 21 — Insufficient Anti-Automation

Frequently Asked Questions

What is CWE-799?

CWE-799 (Improper Control of Interaction Frequency) is a software weakness identified by MITRE's Common Weakness Enumeration. It is classified as a Class-level weakness. The product does not properly limit the number or frequency of interactions that it has with an actor, such as the number of incoming requests.

How can CWE-799 be exploited?

Attackers can exploit CWE-799 (Improper Control of Interaction Frequency) to dos: resource consumption (other), bypass protection mechanism, other. This weakness is typically introduced during the Architecture and Design, Implementation, Operation phase of software development.

How do I prevent CWE-799?

Follow secure coding practices, conduct code reviews, and use automated security testing tools (SAST/DAST) to detect this weakness early in the development lifecycle.

What is the severity of CWE-799?

CWE-799 is classified as a Class-level weakness (High abstraction). It has been observed in 2 real-world CVEs.