CVE-2022-29167Network attack vector

Denial of service via exponential Host-header parsing

Published May 5, 2022 · Updated Apr 23, 2025

Regular expression denial of service in Mozilla Hawk before 9.0.1 allows remote attackers to hang a Node.js service via a crafted Host header. Hawk.utils.parseHost() applies an exponentially slow regular expression to attacker-controlled Host values instead of using a bounded URL parser. The vulnerable path is reached when Hawk.authenticate() derives host and port from the request; supplying both options bypasses parsing, and sustained CPU consumption can interrupt the hosting service.

CVSS severity7.5
High
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in Mozilla Hawk before 9.0.1 allows remote attackers to hang a Node.js service via a crafted Host header. Hawk.utils.parseHost() applies an exponentially slow regular expression to attacker-controlled Host values instead of using a bounded URL parser. The vulnerable path is reached when Hawk.authenticate() derives host and port from the request; supplying both options bypasses parsing, and sustained CPU consumption can interrupt the hosting service.

The record

CVE
CVE-2022-29167
Published
May 5, 2022
Updated
Apr 23, 2025
Vendor
Mozilla
Product
Hawk
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 5, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record 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=< 9.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Hawkversion=< 9.0.1

Published CVSS scores

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

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 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-400Uncontrolled Resource Consumption
T1499Endpoint 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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