// For flags

CVE-2021-40797

openstack-neutron: Routes middleware memory leak for nonexistent controllers

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

< 1%
*EPSS

Affected Versions

3
*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

An issue was discovered in the routes middleware in OpenStack Neutron before 16.4.1, 17.x before 17.2.1, and 18.x before 18.1.1. By making API requests involving nonexistent controllers, an authenticated user may cause the API worker to consume increasing amounts of memory, resulting in API performance degradation or denial of service.

Se ha detectado un problema en el middleware de rutas en OpenStack Neutron versiones anteriores a 16.4.1, 17.x versiones anteriores a 17.2.1 y 18.x versiones anteriores a 18.1.1. Al llevar a cabo peticiones a la API que implican a controladores no existentes, un usuario autenticado puede causar que el trabajador de la API consuma cantidades crecientes de memoria, resultando en una degradación del rendimiento de la API o una denegación de servicio

A resource-allocation flaw was found in openstack-neutron. An authenticated attacker could make API requests involving nonexistent controllers causing the API worker to consume increasing amounts of memory. This flaw could be exploited to force API performance degradation or denial of service.

David Sinquin discovered that OpenStack Neutron incorrectly handled the default Open vSwitch firewall rules. An attacker could possibly use this issue to impersonate the IPv6 addresses of other systems on the network. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. Jake Yip and Justin Mammarella discovered that OpenStack Neutron incorrectly handled the linuxbridge driver when ebtables-nft is being used. An attacker could possibly use this issue to impersonate the hardware address of other systems on the network. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-09-08 CVE Reserved
  • 2021-09-08 CVE Published
  • 2024-08-04 CVE Updated
  • 2024-08-04 First Exploit
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-770: Allocation of Resources Without Limits or Throttling
  • CWE-772: Missing Release of Resource after Effective Lifetime
CAPEC
Affected Vendors, Products, and Versions (3)