Symptom
A vulnerability in the Tool Command Language (Tcl) interpreter of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker with privileged EXEC credentials to execute arbitrary code on the underlying operating system (OS) with root privileges.
The vulnerability is due to insufficient input validation of data passed to the Tcl interpreter. An attacker could exploit this vulnerability by loading malicious Tcl code on an affected device. A successful exploit could allow the attacker to cause memory corruption or execute the code with root privileges on the underlying OS of the affected device.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
Cisco has published a security advisory containing additional details which is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcl-ace-C9KuVKmm
Conditions
For information on fixed versions of software consult the Cisco IOS Software checker:
https://tools.cisco.com/security/center/softwarechecker.x
See Vulnerable Products Section of the advisory for full details:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcl-ace-C9KuVKmm
Workaround
There are no workarounds that address this vulnerability.
Further Problem Description
Please refer to the Security Advisory.
PSIRT Evaluation
The Cisco PSIRT has assigned this bug the following CVSS version 3 score. The Base CVSS score as of the time of evaluation is 6.7:
https://tools.cisco.com/security/center/cvssCalculator.x?version=3.0&vector=CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVE ID CVE-2020-3204 has been assigned to document this issue.
Additional information on Cisco''s security vulnerability policy can be found at the following URL:
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
