CVE-2022-34472Network attack vector

Revoked-certificate acceptance via stale PAC loading state

Published Dec 22, 2022 · Updated Apr 15, 2025

Improper PAC failure handling in Mozilla Firefox before 102, Firefox ESR before 91.11, and Thunderbird before 102 allows attackers to bypass OCSP. The networking code leaves GetIsPACLoading true after the configured PAC URL fails to load, so certificate verification suppresses OCSP requests while ordinary traffic proceeds directly. A PAC URL must be configured and unreachable, and a user must visit content using a revoked certificate; the failure can permit that certificate to be accepted.

CVSS severity4.3
Medium
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper PAC failure handling in Mozilla Firefox before 102, Firefox ESR before 91.11, and Thunderbird before 102 allows attackers to bypass OCSP. The networking code leaves GetIsPACLoading true after the configured PAC URL fails to load, so certificate verification suppresses OCSP requests while ordinary traffic proceeds directly. A PAC URL must be configured and unreachable, and a user must visit content using a revoked certificate; the failure can permit that certificate to be accepted.

The record

CVE
CVE-2022-34472
Published
Dec 22, 2022
Updated
Apr 15, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-703
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 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=unspecified <102

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <102
Mozilla · Thunderbirdversion=unspecified <102; version=unspecified <91.11
Mozilla · Firefox ESRversion=unspecified <91.11

Published CVSS scores

4.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

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-703Improper Check or Handling of Exceptional Conditions

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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