CVE-2021-3827

What it is

A flaw was found in keycloak, where the default ECP binding flow allows other authentication flows to be bypassed. By exploiting this behavior, an attacker can bypass the MFA authentication by sending a SOAP request with an AuthnRequest and Authorization header with the user's credentials. The highest threat from this vulnerability is to confidentiality and integrity.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering.

Exploit odds

1.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2022-08-23 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:05 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.2% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2022-08-23 16:15 UTC

Last modified

2026-06-17 04:05 UTC

Exploit probability

1.2% · EPSS, next 30 days

Weakness

CWE-287 · Improper authentication

Record status

Modified

Affected

• Redhat Keycloak < 18.0.0
• Redhat Single sign-on 7.0
• Redhat Single sign-on 7.5.0
• Redhat Openshift Container Platform 4.8
• Redhat Openshift Container Platform 4.9

Attack profile CVSS 3.1 · 6.8

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-3827.md and follow it. Check whether this project is affected by CVE-2021-3827. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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