CVE-2021-20289Network attack vector

Endpoint metadata disclosure via conversion error responses

Published Mar 26, 2021 · Updated Aug 3, 2024

Information disclosure in Red Hat RESTEasy 4.6.0.Final and earlier allows remote attackers to obtain endpoint class and method names. The parameter-conversion exception path includes matched JAX-RS resource class and method identifiers in the HTTP response when path, query, or matrix values cannot be converted. Exploitation requires an unauthenticated request to an application-defined typed parameter, and the resulting exposure is limited to endpoint metadata.

CVSS severity5.3
Medium
EPSS probability1.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Red Hat RESTEasy 4.6.0.Final and earlier allows remote attackers to obtain endpoint class and method names. The parameter-conversion exception path includes matched JAX-RS resource class and method identifiers in the HTTP response when path, query, or matrix values cannot be converted. Exploitation requires an unauthenticated request to an application-defined typed parameter, and the resulting exposure is limited to endpoint metadata.

The record

CVE
CVE-2021-20289
Published
Mar 26, 2021
Updated
Aug 3, 2024
Vendor
Red Hat
Product
RESTEasy
Classifications
CWE-209
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=resteasy 3.11.5.Final, resteasy 3.15.2.Final, resteasy 4.5.10.Final, resteasy 4.6.1.Final, resteasy 4.6.2.Final

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Red Hat · RESTEasyversion=resteasy 3.11.5.Final, resteasy 3.15.2.Final, resteasy 4.5.10.Final, resteasy 4.6.1.Final, resteasy 4.6.2.Final

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-209Generation of Error Message Containing Sensitive Information

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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