CVE-2020-27831Network attack vector

Unauthorized notification enrollment via unprotected authorization token

Published May 26, 2021 · Updated Aug 4, 2024

Authorization bypass in Red Hat Quay before 3.3.3 allows remote authenticated users to add unowned addresses to repository email notifications. The email-verification flow fails to protect the authorization token that proves control of a submitted address; no more specific code locus is public. Repository administration privileges are required, and successful exploitation changes notification recipients without any published broader impact.

CVSS severity4.3
Medium
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authorization bypass in Red Hat Quay before 3.3.3 allows remote authenticated users to add unowned addresses to repository email notifications. The email-verification flow fails to protect the authorization token that proves control of a submitted address; no more specific code locus is public. Repository administration privileges are required, and successful exploitation changes notification recipients without any published broader impact.

The record

CVE
CVE-2020-27831
Published
May 26, 2021
Updated
Aug 4, 2024
Vendor
Red Hat
Product
Red Hat Quay
Classifications
CWE-284, CWE-522
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Quay 3.3.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Red Hat · Red Hat Quayversion=Quay 3.3.3

Published CVSS scores

4.0NVDAV:N/AC:L/Au:S/C:N/I:P/A:N
4.3NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CWE-522Insufficiently Protected Credentials

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo