CVE-2020-2655Public exploitNetwork attack vector

TLS client-authentication bypass via omitted CertificateVerify

Published Jan 15, 2020 · Updated Sep 30, 2024

Authentication bypass in Oracle Java SE 11.0.5 and 13.0.1 JSSE allows remote attackers to access TLS-protected application data. The JSSE server state machine completes a TLS handshake when a client omits CertificateVerify, so required certificate possession is never proven. Exploitation requires an application that uses affected JSSE APIs for TLS client authentication; success permits unauthenticated reading or modification of application data.

CVSS severity4.8
Medium
EPSS probability3.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Oracle Java SE 11.0.5 and 13.0.1 JSSE allows remote attackers to access TLS-protected application data. The JSSE server state machine completes a TLS handshake when a client omits CertificateVerify, so required certificate possession is never proven. Exploitation requires an application that uses affected JSSE APIs for TLS client authentication; success permits unauthenticated reading or modification of application data.

The record

CVE
CVE-2020-2655
Published
Jan 15, 2020
Updated
Sep 30, 2024
Vendor
Oracle Corporation
Product
Java Platform, Standard Edition (Java SE)
Classifications
CWE-841, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 30, 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=Java SE: 11.0.5, 13.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oracle Corporation · Java Platform, Standard Edition (Java SE)version=Java SE: 11.0.5, 13.0.1

Published CVSS scores

4.8Oracle CorporationCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/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 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 exploitPublished

Weakness, pattern, technique

CWE-841Improper Enforcement of Behavioral Workflow
T1190Exploit Public-Facing Application

Public exploit references

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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