CVE-2024-34447Network attack vector

Certificate validation bypass via DNS-derived peer identity

Published May 3, 2024 · Updated Jun 17, 2025

Certificate validation in Bouncy Castle BCJSSE before 1.0.19 allows remote attackers to redirect HTTPS traffic via DNS poisoning. When HttpsURLConnection creates an SSL socket without an explicit hostname, BCJSSE derives the peer identity from the DNS-resolved address and verifies the certificate against that identity rather than the original URL hostname. Endpoint identification must be enabled, and successful DNS poisoning can cause the client to accept an attacker-controlled endpoint for the poisoned destination.

CVSS severity5.9
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Certificate validation in Bouncy Castle BCJSSE before 1.0.19 allows remote attackers to redirect HTTPS traffic via DNS poisoning. When HttpsURLConnection creates an SSL socket without an explicit hostname, BCJSSE derives the peer identity from the DNS-resolved address and verifies the certificate against that identity rather than the original URL hostname. Endpoint identification must be enabled, and successful DNS poisoning can cause the client to accept an attacker-controlled endpoint for the poisoned destination.

The record

CVE
CVE-2024-34447
Published
May 3, 2024
Updated
Jun 17, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-297, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 3, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 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

7.5CISA ADP VulnrichmentCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.9GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/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 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-297Improper Validation of Certificate with Host Mismatch
T1557Adversary-in-the-Middle

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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