CVE-2020-3201: Cisco IOS and IOS XE Software Tcl Denial of Service Vulnerability

Severity: medium (CVSS 6.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-06-03 · updated 2026-06-17
Weakness: CWE-20

Description

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: 12.2(18)ixa, 12.2(18)ixb, 12.2(18)ixb1, 12.2(18)ixb2, 12.2(18)ixc, 12.2(18)ixd (+1664)
Cisco IOS XE: 3.2.0sg, 3.2.1sg, 3.2.2sg, 3.2.3sg, 3.2.4sg, 3.2.5sg (+241)

References

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