CVE-2023-20033Network attack vector

Device reload via management-interface traffic flood

Published Sep 27, 2023 · Updated Jun 18, 2025

Resource exhaustion in Cisco IOS XE Software on Catalyst 3650 and 3850 switches allows remote attackers to force a device reload. Traffic arriving at an enabled management interface is processed without adequate resource controls, so a sustained high rate exhausts the device and triggers the reload. The interface must be enabled and reachable; exploitation requires no authentication and interrupts availability during the unexpected reload.

CVSS severity8.6
High
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Cisco IOS XE Software on Catalyst 3650 and 3850 switches allows remote attackers to force a device reload. Traffic arriving at an enabled management interface is processed without adequate resource controls, so a sustained high rate exhausts the device and triggers the reload. The interface must be enabled and reachable; exploitation requires no authentication and interrupts availability during the unexpected reload.

The record

CVE
CVE-2023-20033
Published
Sep 27, 2023
Updated
Jun 18, 2025
Vendor
ClamAV
Product
Cisco IOS XE Software
Classifications
CWE-770, CAPEC-125, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 18, 2025Record 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=16.11.1
  2. Affected versionversion=16.11.1s
  3. Affected versionversion=16.11.2
  4. Affected versionversion=16.12.1
  5. Affected versionversion=16.12.1s
  6. Affected versionversion=16.12.2
  7. Affected versionversion=16.12.3
  8. Affected versionversion=16.12.3a
  9. Affected versionversion=16.12.3s
  10. Affected versionversion=16.12.4
  11. Affected versionversion=16.12.5
  12. Affected versionversion=16.12.5b
  13. Affected versionversion=16.12.6
  14. Affected versionversion=16.12.6a
  15. Affected versionversion=16.12.7
  16. Affected versionversion=16.12.8
  17. Affected versionversion=16.12.9
  18. Affected versionversion=16.3.1
  19. Affected versionversion=16.3.10
  20. Affected versionversion=16.3.11
  21. Affected versionversion=16.3.1a
  22. Affected versionversion=16.3.2
  23. Affected versionversion=16.3.3
  24. Affected versionversion=16.3.4
  25. Affected versionversion=16.3.5
  26. Affected versionversion=16.3.5b
  27. Affected versionversion=16.3.6
  28. Affected versionversion=16.3.7
  29. Affected versionversion=16.3.8
  30. Affected versionversion=16.3.9
  31. Affected versionversion=16.4.1
  32. Affected versionversion=16.5.1
  33. Affected versionversion=16.5.1a
  34. Affected versionversion=16.6.1
  35. Affected versionversion=16.6.10
  36. Affected versionversion=16.6.2
  37. Affected versionversion=16.6.3
  38. Affected versionversion=16.6.4
  39. Affected versionversion=16.6.4a
  40. Affected versionversion=16.6.5
  41. Affected versionversion=16.6.6
  42. Affected versionversion=16.6.7
  43. Affected versionversion=16.6.8
  44. Affected versionversion=16.6.9
  45. Affected versionversion=16.7.1
  46. Affected versionversion=16.8.1
  47. Affected versionversion=16.8.1a
  48. Affected versionversion=16.8.1s
  49. Affected versionversion=16.9.1
  50. Affected versionversion=16.9.1s
  51. Affected versionversion=16.9.2
  52. Affected versionversion=16.9.3
  53. Affected versionversion=16.9.3a
  54. Affected versionversion=16.9.4
  55. Affected versionversion=16.9.5
  56. Affected versionversion=16.9.6
  57. Affected versionversion=16.9.7
  58. Affected versionversion=16.9.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco IOS XE Softwareversion=16.11.1; version=16.11.1s; version=16.11.2; version=16.12.1; version=16.12.1s; version=16.12.2; version=16.12.3; version=16.12.3a; version=16.12.3s; version=16.12.4; version=16.12.5; version=16.12.5b; version=16.12.6; version=16.12.6a; version=16.12.7; version=16.12.8; version=16.12.9; version=16.3.1; version=16.3.10; version=16.3.11; version=16.3.1a; version=16.3.2; version=16.3.3; version=16.3.4; version=16.3.5; version=16.3.5b; version=16.3.6; version=16.3.7; version=16.3.8; version=16.3.9; version=16.4.1; version=16.5.1; version=16.5.1a; version=16.6.1; version=16.6.10; version=16.6.2; version=16.6.3; version=16.6.4; version=16.6.4a; version=16.6.5; version=16.6.6; version=16.6.7; version=16.6.8; version=16.6.9; version=16.7.1; version=16.8.1; version=16.8.1a; version=16.8.1s; version=16.9.1; version=16.9.1s; version=16.9.2; version=16.9.3; version=16.9.3a; version=16.9.4; version=16.9.5; version=16.9.6; version=16.9.7; version=16.9.8

Published CVSS scores

8.6CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X

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-770Allocation of Resources Without Limits or Throttling
CAPEC-125Flooding
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

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Your stack

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