CVE-2022-43705Network attack vector

Certificate revocation bypass via unauthorized OCSP signer

Published Nov 27, 2022 · Updated Apr 25, 2025

Improper certificate validation in Botan 1.11.34 through 2.19.2 allows man-in-the-middle attackers to forge OCSP revocation status. OCSP response validation accepts any valid signature from an embedded responder certificate without verifying that the issuing CA authorized that responder. An attacker able to spoof or staple a response can mark legitimate certificates revoked or present a revoked certificate as valid, enabling TLS server impersonation when applications rely on OCSP.

CVSS severity6.5
Medium
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Botan 1.11.34 through 2.19.2 allows man-in-the-middle attackers to forge OCSP revocation status. OCSP response validation accepts any valid signature from an embedded responder certificate without verifying that the issuing CA authorized that responder. An attacker able to spoof or staple a response can mark legitimate certificates revoked or present a revoked certificate as valid, enabling TLS server impersonation when applications rely on OCSP.

The record

CVE
CVE-2022-43705
Published
Nov 27, 2022
Updated
Apr 25, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-295, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 27, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 25, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
6.5randombitCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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.

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-295Improper Certificate Validation
T1557Adversary-in-the-Middle

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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