CVE-2024-20303

Adjacent service interruption via mishandled mDNS entries

Published Mar 27, 2024 · Updated Aug 1, 2024

Denial of service in Cisco IOS XE Software for WLCs allows physically proximate attackers to interrupt wireless access with mDNS traffic. The mDNS gateway improperly manages client entries while processing a continuous stream of specific mDNS packets, driving controller CPU utilization high. Exploitation requires wireless-network access, the mDNS gateway enabled, and APs managed in FlexConnect mode; affected APs can lose their controller connections.

CVSS severity7.4
High
EPSS probability0.32%
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

Denial of service in Cisco IOS XE Software for WLCs allows physically proximate attackers to interrupt wireless access with mDNS traffic. The mDNS gateway improperly manages client entries while processing a continuous stream of specific mDNS packets, driving controller CPU utilization high. Exploitation requires wireless-network access, the mDNS gateway enabled, and APs managed in FlexConnect mode; affected APs can lose their controller connections.

The record

CVE
CVE-2024-20303
Published
Mar 27, 2024
Updated
Aug 1, 2024
Vendor
ClamAV
Product
Cisco IOS XE Software
Classifications
CWE-459, T1498.001
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 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=17.10.1
  2. Affected versionversion=17.10.1a
  3. Affected versionversion=17.10.1b
  4. Affected versionversion=17.11.1
  5. Affected versionversion=17.11.1a
  6. Affected versionversion=17.11.99SW
  7. Affected versionversion=17.2.1
  8. Affected versionversion=17.2.1a
  9. Affected versionversion=17.2.1r
  10. Affected versionversion=17.2.1v
  11. Affected versionversion=17.2.2
  12. Affected versionversion=17.2.3
  13. Affected versionversion=17.3.1
  14. Affected versionversion=17.3.1a
  15. Affected versionversion=17.3.1w
  16. Affected versionversion=17.3.1x
  17. Affected versionversion=17.3.1z
  18. Affected versionversion=17.3.2
  19. Affected versionversion=17.3.2a
  20. Affected versionversion=17.3.3
  21. Affected versionversion=17.3.4
  22. Affected versionversion=17.3.4a
  23. Affected versionversion=17.3.4b
  24. Affected versionversion=17.3.4c
  25. Affected versionversion=17.3.5
  26. Affected versionversion=17.3.5a
  27. Affected versionversion=17.3.5b
  28. Affected versionversion=17.3.6
  29. Affected versionversion=17.3.7
  30. Affected versionversion=17.3.8
  31. Affected versionversion=17.3.8a
  32. Affected versionversion=17.4.1
  33. Affected versionversion=17.4.1a
  34. Affected versionversion=17.4.1b
  35. Affected versionversion=17.4.2
  36. Affected versionversion=17.4.2a
  37. Affected versionversion=17.5.1
  38. Affected versionversion=17.5.1a
  39. Affected versionversion=17.6.1
  40. Affected versionversion=17.6.1a
  41. Affected versionversion=17.6.1w
  42. Affected versionversion=17.6.1x
  43. Affected versionversion=17.6.1y
  44. Affected versionversion=17.6.1z
  45. Affected versionversion=17.6.1z1
  46. Affected versionversion=17.6.2
  47. Affected versionversion=17.6.3
  48. Affected versionversion=17.6.3a
  49. Affected versionversion=17.6.4
  50. Affected versionversion=17.6.5
  51. Affected versionversion=17.6.5a
  52. Affected versionversion=17.7.1
  53. Affected versionversion=17.7.1a
  54. Affected versionversion=17.7.1b
  55. Affected versionversion=17.7.2
  56. Affected versionversion=17.8.1
  57. Affected versionversion=17.8.1a
  58. Affected versionversion=17.9.1
  59. Affected versionversion=17.9.1a
  60. Affected versionversion=17.9.1w
  61. Affected versionversion=17.9.1x
  62. Affected versionversion=17.9.1x1
  63. Affected versionversion=17.9.1y
  64. Affected versionversion=17.9.1y1
  65. Affected versionversion=17.9.2
  66. Affected versionversion=17.9.2a
  67. Affected versionversion=17.9.3
  68. Affected versionversion=17.9.3a

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco IOS XE Softwareversion=17.10.1; version=17.10.1a; version=17.10.1b; version=17.11.1; version=17.11.1a; version=17.11.99SW; version=17.2.1; version=17.2.1a; version=17.2.1r; version=17.2.1v; version=17.2.2; version=17.2.3; version=17.3.1; version=17.3.1a; version=17.3.1w; version=17.3.1x; version=17.3.1z; version=17.3.2; version=17.3.2a; version=17.3.3; version=17.3.4; version=17.3.4a; version=17.3.4b; version=17.3.4c; version=17.3.5; version=17.3.5a; version=17.3.5b; version=17.3.6; version=17.3.7; version=17.3.8; version=17.3.8a; version=17.4.1; version=17.4.1a; version=17.4.1b; version=17.4.2; version=17.4.2a; version=17.5.1; version=17.5.1a; version=17.6.1; version=17.6.1a; version=17.6.1w; version=17.6.1x; version=17.6.1y; version=17.6.1z; version=17.6.1z1; version=17.6.2; version=17.6.3; version=17.6.3a; version=17.6.4; version=17.6.5; version=17.6.5a; version=17.7.1; version=17.7.1a; version=17.7.1b; version=17.7.2; version=17.8.1; version=17.8.1a; version=17.9.1; version=17.9.1a; version=17.9.1w; version=17.9.1x; version=17.9.1x1; version=17.9.1y; version=17.9.1y1; version=17.9.2; version=17.9.2a; version=17.9.3; version=17.9.3a

Published CVSS scores

7.4Cisco Systems, Inc.CVSS:3.1/AV:A/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-459Incomplete Cleanup
T1498.001Direct Network Flood

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