Overview
On August 28, 2019, local time, Cisco released a security advisory, announcing remediation of an authentication bypass vulnerability (CVE-2019-12643) in the Cisco REST API virtual service container for Cisco IOS XE Software.
The vulnerability is due to an improper check performed by the area of code that manages the REST API authentication service. An attacker could exploit this vulnerability by submitting malicious HTTP requests to the targeted device.
Successful exploitation could allow the attacker to obtain the token-id of an authenticated user. This token-id could be used to bypass authentication and execute privileged actions through the interface of the REST API virtual service container on the affected Cisco IOS XE device.
The REST API interface is not enabled by default and must be installed and activated separately on IOS XE devices.
CVSS 3.0 score:
Base 10.0 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:X/RL:X/RC:X
Reference:
Affected Products
This vulnerability exists in the Cisco REST API virtual service container and affects Cisco IOS XE devices that are configured to use a vulnerable version of Cisco REST API virtual service container. At the time of publication, this vulnerability affected the following products:
- Cisco 4000 Series Integrated Services Routers
- Cisco ASR 1000 Series Aggregation Services Routers
- Cisco Cloud Services Router 1000V Series
- Cisco Integrated Services Virtual Router
Note: For specific versions of the Cisco REST API virtual service containers that are affected by this vulnerability, see the official security advisory available at the following link:
Unaffected Products
- REST API virtual service container: iosxe-remote-mgmt.16.09.03.ova
- Cisco has confirmed that this vulnerability does not affect Cisco IOS Software, Cisco IOS XR Software, and Cisco NX-OS Software.
Solution
Cisco has released a fixed version of the REST API virtual service container. Cisco has also released a hardened Cisco IOS XE Software release that prevents installation or activation of a vulnerable container on a device. If the device was already configured with an active vulnerable container, upgrading the IOS XE Software will deactivate the container, making the device not vulnerable. In that case, to restore the REST API functionality, customers should upgrade the Cisco REST API virtual service container to a fixed software release.
The fixed version is available at the following link:
https://software.cisco.com/download/home/284364978/type/286283116/release/16.9.3
Statement
This advisory is only used to describe a potential risk. NSFOCUS does not provide any commitment or promise on this advisory. NSFOCUS and the author will not bear any liability for any direct and/or indirect consequences and losses caused by transmitting and/or using this advisory. NSFOCUS reserves all the rights to modify and interpret this advisory. Please include this statement paragraph when reproducing or transferring this advisory. Do not modify this advisory, add/delete any information to/from it, or use this advisory for commercial purposes without permission from NSFOCUS.
About NSFOCUS
NSFOCUS, Inc., a global network and cyber security leader, protects enterprises and carriers from advanced cyber attacks. The company’s Intelligent Hybrid Security strategy utilizes both cloud and on-premises security platforms, built on a foundation of real-time global threat intelligence, to provide multi-layered, unified and dynamic protection against advanced cyber attacks.
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