# CVE-2019-3875: Improper Certificate Validation and Insufficient Verification of Data Authenticity in Keycloak

> Attackers can bypass certificate revocation checks in Keycloak by exploiting missing CRL signature validation, potentially allowing revoked certificates to be accepted.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Jun 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-38cg-gg9j-q9j9

## What is CVE-2019-3875?

CVE-2019-3875 is a medium-severity vulnerability in Redhat Keycloak, published on 12 Jun 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was found in keycloak before 6.0.2. The X.509 authenticator supports the verification of client certificates through the CRL, where the CRL list can be obtained from the URL provided in the certificate itself (CDP) or through the separately configured path. The CRL are often available over the network through unsecured protocols ('http' or 'ldap') and hence the caller should verify the signature and possibly the certification path. Keycloak currently doesn't validate signatures on CRL, which can result in a possibility of various attacks like man-in-the-middle.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity), CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2019-3875?

2 open source packages ship an affected version, including org.keycloak:keycloak-core. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.keycloak:keycloak-core` | Maven | All versions to 6.0.1 | None |
| `org.keycloak:keycloak-core` | Maven | All versions to 6.0.1 | None |

Products: Redhat Keycloak, Redhat Single Sign-On.

## How do I fix CVE-2019-3875?

No fix has been published for CVE-2019-3875 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-3875 being exploited?

There is no known exploitation of CVE-2019-3875 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Keycloak

- [CVE-2022-4361](https://insights.sbomify.com/CVE-2022-4361/): Keycloak vulnerable to cross-site scripting when validating URI-schemes on SAML and OIDC (critical 10.0)
- [CVE-2022-1245](https://insights.sbomify.com/CVE-2022-1245/): Keycloak vulnerable to privilege escalation on Token Exchange feature (critical 9.8)
- [CVE-2021-20195](https://insights.sbomify.com/CVE-2021-20195/): keycloak Self Stored Cross-site Scripting vulnerability (critical 9.6)
- [CVE-2019-14910](https://insights.sbomify.com/CVE-2019-14910/): Keycloak Authentication Error (critical 9.3)
- [CVE-2019-14909](https://insights.sbomify.com/CVE-2019-14909/): Keycloak Authentication Error (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-3875 and fix it if it is affected.

What it is: CVE-2019-3875 is a medium-severity vulnerability in Redhat Keycloak, published on 12 Jun 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-3875 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.keycloak:keycloak-core (Maven): affected all versions up to 6.0.1; no fix listed
- org.keycloak:keycloak-core (Maven): affected all versions up to 6.0.1; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2019-3875/ (Markdown: https://insights.sbomify.com/CVE-2019-3875/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-3875
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-3875
- OSV: https://osv.dev/vulnerability/CVE-2019-3875

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-3875/
Summaries are generated and may contain mistakes; the official description above is the record.