CVE Vulnerabilities

CVE-2021-23049

Uncontrolled Resource Consumption

Published: Sep 14, 2021 | Modified: Sep 24, 2021
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu

On BIG-IP version 16.0.x before 16.0.1.2 and 15.1.x before 15.1.3, when the iRules RESOLVER::summarize command is used on a virtual server, undisclosed requests can cause an increase in Traffic Management Microkernel (TMM) memory utilization resulting in an out-of-memory condition and a denial-of-service (DoS). Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness

The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

Affected Software

Name Vendor Start Version End Version
Big-ip_access_policy_manager F5 15.1.0 *
Big-ip_application_security_manager F5 15.1.0 *
Big-ip_advanced_firewall_manager F5 15.1.0 *
Big-ip_advanced_web_application_firewall F5 15.1.0 *
Big-ip_analytics F5 15.1.0 *
Big-ip_application_acceleration_manager F5 15.1.0 *
Big-ip_domain_name_system F5 15.1.0 *
Big-ip_fraud_protection_service F5 15.1.0 *
Big-ip_global_traffic_manager F5 15.1.0 *
Big-ip_link_controller F5 15.1.0 *
Big-ip_local_traffic_manager F5 15.1.0 *
Big-ip_access_policy_manager F5 16.0.0 *
Big-ip_domain_name_system F5 16.0.0 *
Big-ip_advanced_firewall_manager F5 16.0.0 *
Big-ip_local_traffic_manager F5 16.0.0 *
Big-ip_application_security_manager F5 16.0.0 *
Big-ip_link_controller F5 16.0.0 *
Big-ip_global_traffic_manager F5 16.0.0 *
Big-ip_application_acceleration_manager F5 16.0.0 *
Big-ip_fraud_protection_service F5 16.0.0 *
Big-ip_analytics F5 16.0.0 *
Big-ip_advanced_web_application_firewall F5 16.0.0 *

Extended Description

Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system. There are at least three distinct scenarios which can commonly lead to resource exhaustion:

Resource exhaustion problems are often result due to an incorrect implementation of the following situations:

Potential Mitigations

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

References