Is CVE-2021-1621 in the CISA KEV catalog?

No. CVE-2021-1621 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-1621?

CVE-2021-1621 has a CVSS v3 base score of 7.4 (HIGH).

What is the EPSS score for CVE-2021-1621?

CVE-2021-1621 has an EPSS score of 0.35% (27th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-1621?

Upgrade ios xe to 17.3.1 or later.

CVE & CISA-KEV Catalog

CVE-2021-1621

HIGH

7.4

CVSS v3

NVD

Description

A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a queue wedge on an interface that receives specific Layer 2 frames, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of certain Layer 2 frames. An attacker could exploit this vulnerability by sending specific Layer 2 frames on the segment the router is connected to. A successful exploit could allow the attacker to cause a queue wedge on the interface, resulting in a DoS condition.

CWE-399Resource Management Errors

How to fix

Remediation Available

ios xeNVD

Affected:< 17.3.1Fixed in:17.3.1CVE-2021-1621derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorAdjacent

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeChanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Exploit Intelligence

0.35%probability of exploitation in 30 days

27thpercentile

Low risk: more likely to be exploited than 27% of all known CVEs.

References

Patch1

tools.cisco.com

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.