CVE-2022-20757Network attack vector

Unauthenticated connection drops via high-rate UDP traffic

Published May 3, 2022 · Updated Nov 6, 2024

Denial of service in Cisco Firepower Threat Defense Software allows remote attackers to drop all new connections with high-rate UDP traffic. Its connection-handling path improperly processes traffic after platform limits are reached, exhausting capacity for newly arriving connections. Exposure requires a vulnerable release configured to send traffic to Snort2 or Snort3 when a matching blocking rule is encountered.

CVSS severity8.6
High
EPSS probability1.23%
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 Firepower Threat Defense Software allows remote attackers to drop all new connections with high-rate UDP traffic. Its connection-handling path improperly processes traffic after platform limits are reached, exhausting capacity for newly arriving connections. Exposure requires a vulnerable release configured to send traffic to Snort2 or Snort3 when a matching blocking rule is encountered.

The record

CVE
CVE-2022-20757
Published
May 3, 2022
Updated
Nov 6, 2024
Vendor
ClamAV
Product
Cisco Firepower Threat Defense Software
Classifications
CWE-770, T1498.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 3, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 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=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Firepower Threat Defense Softwareversion=n/a

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
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

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Your stack

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