A vulnerability in the request system shell command supported by specific Cisco IOS XE platforms (WS-C3850, WS-C3650, AIR-CT5760, and WS-C4500X) could allow an authenticated, local attacker with administrative privilege (15) to access the underlying Linux root shell.
The vulnerability is due to improper parsing of the challenge response. An attacker could exploit this vulnerability by entering a crafted challenge response. An exploit could allow the attacker to compromise the system. The request system shell command is available only if the service internal command is configured, which is not recommended.
Cisco has confirmed the vulnerability in a security notice; however, software updates are not available.
To exploit this vulnerability, an attacker must authenticate and have local access to the targeted device. These access requirements could reduce the possibility 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.
Customers are advised to consult Cisco bug ID CSCur09815 for a complete list of affected product versions.
Vulnerable ProductsAt the time this alert was first published, Cisco IOS XE Software Releases 3.5E and prior were vulnerable. Later releases of Cisco IOS XE Software may also be vulnerable.
Products Confirmed Not VulnerableNo other Cisco products are currently known to be affected by these vulnerabilities.
Administrators are advised to contact the vendor regarding future updates and releases.
Administrators are advised to allow only privileged users to access administration or management systems.
Administrators are advised to allow only trusted users to access local systems.
Administrators are advised to monitor affected systems.
Software updates are not 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 2014-Nov-06
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