A vulnerability in the Representational State Transfer (REST) application programming interface (API) of the Cisco Access Control Server (ACS) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to how the ACS REST API handles increased traffic load. An attacker could exploit this vulnerability by sending large numbers of requests to a targeted device to increase traffic load on the device. An exploit could allow the attacker to cause the ACS REST API to reject or fail to service valid requests, resulting in a DoS condition. Cisco has confirmed the vulnerability; however, software updates are not available. To exploit this vulnerability, an attacker may need access to trusted, internal networks to send large numbers of requests to the affected device. This access requirement may reduce the likelihood of a successful exploit. Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
| Version | Description | Section | Status | Date |
| 1.0 | Initial Release | NA | Final | 2015-May-21 |
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A stand-alone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy, and may lack important information or contain factual errors. The information in this document is intended for end-users of Cisco products.
Vulmon