CVE-2020-3204

CVE-2020-3204 is a medium-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 6.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

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 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.

Frequently asked questions

What is CVE-2020-3204?
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.
How severe is CVE-2020-3204?
CVE-2020-3204 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-3204 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3204?
CVE-2020-3204 primarily affects Cisco Ios. In total, 1283 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3204?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3204 published?
CVE-2020-3204 was published on 2020-06-03 and last updated on 2026-06-17.

References

Affected products (1283)

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