CVE Vulnerabilities

CVE-2018-0092

Missing Authorization

Published: Jan 18, 2018 | Modified: Oct 09, 2019
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CVSS 2.x
3.6 LOW
AV:L/AC:L/Au:N/C:N/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the network-operator user role implementation for Cisco NX-OS System Software could allow an authenticated, local attacker to improperly delete valid user accounts. The network-operator role should not be able to delete other configured users on the device. The vulnerability is due to a lack of proper role-based access control (RBAC) checks for the actions that a user with the network-operator role is allowed to perform. An attacker could exploit this vulnerability by authenticating to the device with user credentials that give that user the network-operator role. Successful exploitation could allow the attacker to impact the integrity of the device by deleting configured user credentials. The attacker would need valid user credentials for the device. This vulnerability affects the following Cisco products running Cisco NX-OS System Software: Nexus 3000 Series Switches, Nexus 3600 Platform Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCvg21120.

Weakness

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Affected Software

Name Vendor Start Version End Version
Nx-os Cisco 7.0(3)i5(2) 7.0(3)i5(2)
Nx-os Cisco 7.0(3)i6(1) 7.0(3)i6(1)
Nx-os Cisco 7.0(3)i7(1) 7.0(3)i7(1)

Extended Description

Assuming a user with a given identity, authorization is the process of determining whether that user can access a given resource, based on the user’s privileges and any permissions or other access-control specifications that apply to the resource. When access control checks are not applied, users are able to access data or perform actions that they should not be allowed to perform. This can lead to a wide range of problems, including information exposures, denial of service, and arbitrary code execution.

Potential Mitigations

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
  • Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
  • For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
  • One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.

References