CVE-2020-3201: Cisco IOS

Medium severity, CVSS 6.0. EPSS: 0.3% chance of exploitation in the next 30 days.

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 cause a denial of service (DoS) condition on an affected system. The vulnerability is due to insufficient input validation of data passed to the Tcl interpreter. An attacker could exploit this vulnerability by executing crafted Tcl arguments on an affected device. An exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Affected products

• Cisco IOS: version 12.2(18)ixa only; version 12.2(18)ixb only; version 12.2(18)ixb1 only; version 12.2(18)ixb2 only; version 12.2(18)ixc only; version 12.2(18)ixd only; …
• Cisco IOS XE: version 3.2.0sg only; version 3.2.1sg only; version 3.2.2sg only; version 3.2.3sg only; version 3.2.4sg only; version 3.2.5sg only; …

Published 2020-06-03. Last modified 2026-06-17.