CVE-2024-20304Network attack vector

UDP service disruption via Mtrace2 packet memory leak

Published Sep 11, 2024 · Updated Sep 11, 2024

Denial of service in Cisco IOS XR Software 7.7.1 through 7.11.2 and 24.1.1 through 24.2.11 allows remote attackers to disrupt UDP services. The Mtrace2 handler fails to release packet memory for crafted IPv4 or IPv6 traffic on UDP port 33433, allowing IGMP or MLD packet counts to rise until higher-level UDP protocols cannot be processed. Exposure requires an active multicast RPM; releases 24.1.1 through 24.2.11 also require multicast configuration, while earlier affected releases do not.

CVSS severity8.6
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco IOS XR Software 7.7.1 through 7.11.2 and 24.1.1 through 24.2.11 allows remote attackers to disrupt UDP services. The Mtrace2 handler fails to release packet memory for crafted IPv4 or IPv6 traffic on UDP port 33433, allowing IGMP or MLD packet counts to rise until higher-level UDP protocols cannot be processed. Exposure requires an active multicast RPM; releases 24.1.1 through 24.2.11 also require multicast configuration, while earlier affected releases do not.

The record

CVE
CVE-2024-20304
Published
Sep 11, 2024
Updated
Sep 11, 2024
Vendor
ClamAV
Product
Cisco IOS XR Software
Classifications
CWE-401, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 11, 2024CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=24.1.1
  2. Affected versionversion=24.1.2
  3. Affected versionversion=24.2.1
  4. Affected versionversion=24.2.11
  5. Affected versionversion=7.10.1
  6. Affected versionversion=7.10.2
  7. Affected versionversion=7.11.1
  8. Affected versionversion=7.11.2
  9. Affected versionversion=7.7.1
  10. Affected versionversion=7.7.2
  11. Affected versionversion=7.7.21
  12. Affected versionversion=7.8.1
  13. Affected versionversion=7.8.12
  14. Affected versionversion=7.8.2
  15. Affected versionversion=7.8.22
  16. Affected versionversion=7.9.1
  17. Affected versionversion=7.9.2
  18. Affected versionversion=7.9.21

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco IOS XR Softwareversion=24.1.1; version=24.1.2; version=24.2.1; version=24.2.11; version=7.10.1; version=7.10.2; version=7.11.1; version=7.11.2; version=7.7.1; version=7.7.2; version=7.7.21; version=7.8.1; version=7.8.12; version=7.8.2; version=7.8.22; version=7.9.1; version=7.9.2; version=7.9.21

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.

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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-401Missing Release of Memory after Effective Lifetime
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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