CVE-2024-20321Network attack vector

eBGP session disruption via shared rate-limiter exhaustion

Published Feb 28, 2024 · Updated Aug 16, 2024

Resource exhaustion in Cisco NX-OS Software allows remote attackers to drop eBGP neighbor sessions by forwarding crafted traffic. The eBGP implementation maps qualifying transit traffic into a shared hardware rate-limiter queue, allowing a flood to exhaust that queue. Exposure requires a listed Nexus switch or line card, a vulnerable release, and at least one eBGP peer; exploitation interrupts routing availability by dropping neighbor sessions.

CVSS severity8.6
High
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Resource exhaustion in Cisco NX-OS Software allows remote attackers to drop eBGP neighbor sessions by forwarding crafted traffic. The eBGP implementation maps qualifying transit traffic into a shared hardware rate-limiter queue, allowing a flood to exhaust that queue. Exposure requires a listed Nexus switch or line card, a vulnerable release, and at least one eBGP peer; exploitation interrupts routing availability by dropping neighbor sessions.

The record

CVE
CVE-2024-20321
Published
Feb 28, 2024
Updated
Aug 16, 2024
Vendor
ClamAV
Product
Cisco NX-OS Software
Classifications
CWE-400, CWE-770, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 28, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.1(1)
  2. Affected versionversion=10.1(2)
  3. Affected versionversion=10.1(2t)
  4. Affected versionversion=10.2(1)
  5. Affected versionversion=10.2(1q)
  6. Affected versionversion=10.2(2)
  7. Affected versionversion=10.2(3)
  8. Affected versionversion=10.2(3t)
  9. Affected versionversion=10.2(3v)
  10. Affected versionversion=10.2(4)
  11. Affected versionversion=10.2(5)
  12. Affected versionversion=10.2(6)
  13. Affected versionversion=10.3(1)
  14. Affected versionversion=10.3(2)
  15. Affected versionversion=10.3(3)
  16. Affected versionversion=10.3(4a)
  17. Affected versionversion=10.3(99w)
  18. Affected versionversion=10.3(99x)
  19. Affected versionversion=10.4(1)
  20. Affected versionversion=7.0(3)F1(1)
  21. Affected versionversion=7.0(3)F2(1)
  22. Affected versionversion=7.0(3)F2(2)
  23. Affected versionversion=7.0(3)F3(1)
  24. Affected versionversion=7.0(3)F3(2)
  25. Affected versionversion=7.0(3)F3(3)
  26. Affected versionversion=7.0(3)F3(3a)
  27. Affected versionversion=7.0(3)F3(3c)
  28. Affected versionversion=7.0(3)F3(4)
  29. Affected versionversion=7.0(3)F3(5)
  30. Affected versionversion=9.2(1)
  31. Affected versionversion=9.2(2)
  32. Affected versionversion=9.2(2t)
  33. Affected versionversion=9.2(2v)
  34. Affected versionversion=9.2(3)
  35. Affected versionversion=9.2(4)
  36. Affected versionversion=9.3(1)
  37. Affected versionversion=9.3(10)
  38. Affected versionversion=9.3(11)
  39. Affected versionversion=9.3(12)
  40. Affected versionversion=9.3(2)
  41. Affected versionversion=9.3(3)
  42. Affected versionversion=9.3(4)
  43. Affected versionversion=9.3(5)
  44. Affected versionversion=9.3(6)
  45. Affected versionversion=9.3(7)
  46. Affected versionversion=9.3(7a)
  47. Affected versionversion=9.3(8)
  48. Affected versionversion=9.3(9)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco NX-OS Softwareversion=10.1(1); version=10.1(2); version=10.1(2t); version=10.2(1); version=10.2(1q); version=10.2(2); version=10.2(3); version=10.2(3t); version=10.2(3v); version=10.2(4); version=10.2(5); version=10.2(6); version=10.3(1); version=10.3(2); version=10.3(3); version=10.3(4a); version=10.3(99w); version=10.3(99x); version=10.4(1); version=7.0(3)F1(1); version=7.0(3)F2(1); version=7.0(3)F2(2); version=7.0(3)F3(1); version=7.0(3)F3(2); version=7.0(3)F3(3); version=7.0(3)F3(3a); version=7.0(3)F3(3c); version=7.0(3)F3(4); version=7.0(3)F3(5); version=9.2(1); version=9.2(2); version=9.2(2t); version=9.2(2v); version=9.2(3); version=9.2(4); version=9.3(1); version=9.3(10); version=9.3(11); version=9.3(12); version=9.3(2); version=9.3(3); version=9.3(4); version=9.3(5); version=9.3(6); version=9.3(7); version=9.3(7a); version=9.3(8); version=9.3(9)
ClamAV · Cisco NX-OSversion=10.1\(1\); version=10.1\(2\); version=10.1\(2t\); version=10.2\(1\); version=10.2\(1q\); version=10.2\(2\); version=10.2\(3\); version=10.2\(3t\); version=10.2\(3v\); version=10.2\(4\); version=10.2\(5\); version=10.2\(6\); version=10.3\(1\); version=10.3\(2\); version=10.3\(3\); version=10.3\(4a\); version=10.3\(99w\); version=10.3\(99x\); version=10.4\(1\); version=7.0\(3\)f1\(1\); version=7.0\(3\)f2\(1\); version=7.0\(3\)f2\(2\); version=7.0\(3\)f3\(1\); version=7.0\(3\)f3\(2\); version=7.0\(3\)f3\(3\); version=7.0\(3\)f3\(3a\); version=7.0\(3\)f3\(3c\); version=7.0\(3\)f3\(4\); version=7.0\(3\)f3\(5\); version=9.2\(1\); version=9.2\(2\); version=9.2\(2t\); version=9.2\(2v\); version=9.2\(3\); version=9.2\(4\); version=9.3\(1\); version=9.3\(10\); version=9.3\(11\); version=9.3\(12\); version=9.3\(2\); version=9.3\(3\); version=9.3\(4\); version=9.3\(5\); version=9.3\(6\); version=9.3\(7\); version=9.3\(7a\); version=9.3\(8\); version=9.3\(9\)

Published CVSS scores

8.6Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
8.6National Institute of Standards and TechnologyCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-770Allocation of Resources Without Limits or Throttling
T1498Network Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo