CVE-2022-0396Network attack vector

DoS via TCP CLOSE_WAIT connection exhaustion

Published Mar 23, 2022 · Updated Sep 16, 2024

Denial of service in BIND 9 9.16.11 through 9.18.0 allows remote attackers to exhaust TCP connection slots via crafted streams. The keep-response-order TCP handling leaves sockets in CLOSE_WAIT indefinitely after clients close, consuming connection capacity. Exploitation requires keep-response-order enabled for the attacker’s ACL; the resulting impact is DNS service interruption, and ISC reports no active exploits.

CVSS severity5.3
Medium
EPSS probability2.70%
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 BIND 9 9.16.11 through 9.18.0 allows remote attackers to exhaust TCP connection slots via crafted streams. The keep-response-order TCP handling leaves sockets in CLOSE_WAIT indefinitely after clients close, consuming connection capacity. Exploitation requires keep-response-order enabled for the attacker’s ACL; the resulting impact is DNS service interruption, and ISC reports no active exploits.

The record

CVE
CVE-2022-0396
Published
Mar 23, 2022
Updated
Sep 16, 2024
Vendor
Internet Systems Consortium
Product
BIND 9
Classifications
CWE-404, T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 23, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=Development Branch 9.17 BIND 9.17 all versions
  2. Affected versionversion=Open Source Branch 9.16 9.16.11 through versions before 9.16.27
  3. Affected versionversion=Open Source Branch 9.18 9.18.0
  4. Affected versionversion=Supported Preview Branch 9.16-S 9.16.11-S through versions before 9.16.27-S

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Internet Systems Consortium · BIND 9version=Development Branch 9.17 BIND 9.17 all versions; version=Open Source Branch 9.16 9.16.11 through versions before 9.16.27; version=Open Source Branch 9.18 9.18.0; version=Supported Preview Branch 9.16-S 9.16.11-S through versions before 9.16.27-S

Published CVSS scores

4.9Internet Systems ConsortiumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:F/RL:O/RC:C
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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-404Improper Resource Shutdown or Release
T1499.002Service Exhaustion

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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