How severe is CVE-2024-20321?

CVE-2024-20321 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2024-20321 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-20321?

CVE-2024-20321 primarily affects Cisco Nx-os. In total, 48 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-20321?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2024-20321 have an EU (EUVD) identifier?

Yes. CVE-2024-20321 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-18036.

When was CVE-2024-20321 published?

CVE-2024-20321 was published on 2024-02-29 and last updated on 2026-06-17.

CVE-2024-20321

CVE-2024-20321 is a high-severity vulnerability in Cisco Nx-os with a CVSS 3.x base score of 8.6. 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-770.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-18036
Weakness: CWE-770
Affected product: Cisco Nx-os
Published: 2024-02-29
Last modified: 2026-06-17

Description

A vulnerability in the External Border Gateway Protocol (eBGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because eBGP traffic is mapped to a shared hardware rate-limiter queue. An attacker could exploit this vulnerability by sending large amounts of network traffic with certain characteristics through an affected device. A successful exploit could allow the attacker to cause eBGP neighbor sessions to be dropped, leading to a DoS condition in the network.

Frequently asked questions

What is CVE-2024-20321?: A vulnerability in the External Border Gateway Protocol (eBGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because eBGP traffic is mapped to a shared hardware rate-limiter queue. An attacker could exploit this vulnerability by sending large amounts of network traffic with certain characteristics through an affected device. A successful exploit could allow the attacker to cause eBGP neighbor sessions to be dropped, leading to a DoS condition in the network.
How severe is CVE-2024-20321?: CVE-2024-20321 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-20321 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-20321?: CVE-2024-20321 primarily affects Cisco Nx-os. In total, 48 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-20321?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2024-20321 have an EU (EUVD) identifier?: Yes. CVE-2024-20321 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-18036.
When was CVE-2024-20321 published?: CVE-2024-20321 was published on 2024-02-29 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-ebgp-dos-L3QCwVJ

Affected products (48)

cpe:2.3:o:cisco:nx-os:7.0\(3\)f1\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f2\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f2\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f3\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f3\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f3\(3\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f3\(3a\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f3\(3c\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f3\(4\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:7.0\(3\)f3\(5\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.2\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.2\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.2\(2t\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.2\(2v\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.2\(3\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.2\(4\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(3\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(4\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(5\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(6\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(7\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(7a\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(8\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(9\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(10\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(11\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:9.3\(12\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.1\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.1\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.1\(2t\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(1q\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(3\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(3t\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(3v\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(4\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:nx-os:10.2\(5\):*:*:*:*:*:*:*

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