Quantum Secular Labs / Blog / Advisories

CVE-2017-6747: Cisco Identity Services Engine: Authentication bypass

CVE-2017-6747 is rated critical with a CVSS v3.0 base score of 9.8 and affects Cisco Identity Services Engine. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

A vulnerability in the authentication module of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to bypass local authentication. The vulnerability is due to improper handling of authentication requests and policy assignment for externally authenticated users. An attacker could exploit this vulnerability by authenticating with a valid external user account that matches an internal username and incorrectly receiving the authorization policy of the internal account. An exploit could allow the attacker to have Super Admin privileges for the ISE Admin portal. This vulnerability does not affect endpoints authenticating to the ISE. The vulnerability affects Cisco ISE, Cisco ISE Express, and Cisco ISE Virtual Appliance running Release 1.3, 1.4, 2.0.0, 2.0.1, or 2.1.0. Release 2.2.x is not affected. Cisco Bug IDs: CSCvb10995.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-287: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

Affected products

  • Cisco Identity Services Engine: 1.3\(0.722\); 1.3\(0.876\); 1.3\(0.909\); 1.3\(106.146\); 1.3\(120.135\); 1.4\(0.109\); 1.4\(0.181\); 1.4\(0.253\); 1.4\(0.908\); 2.0\(0.147\); 2.0\(0.169\); 2.0\(0.222\)

References