# CVE-2020-10776: Cross-site Scripting in keycloak

> Attackers can inject malicious scripts via unsafe redirect_uri schemes in Keycloak, potentially leading to session hijacking or code execution.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 17 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-484q-784p-8m5h

## What is CVE-2020-10776?

CVE-2020-10776 is a medium-severity cross-site scripting vulnerability in Redhat Keycloak, published on 17 Nov 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

A flaw was found in Keycloak before version 12.0.0, where it is possible to add unsafe schemes for the redirect_uri parameter. This flaw allows an attacker to perform a Cross-site scripting attack.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2020-10776?

4 open source packages ship an affected version, including org.keycloak:keycloak-server-spi-private and org.keycloak:keycloak-services. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.keycloak:keycloak-server-spi-private` | Maven | All versions | 12.0.0 |
| `org.keycloak:keycloak-server-spi-private` | Maven | All versions | 12.0.0 |
| `org.keycloak:keycloak-services` | Maven | All versions | 12.0.0 |
| `org.keycloak:keycloak-services` | Maven | All versions | 12.0.0 |

Products: Redhat Keycloak.

## How do I fix CVE-2020-10776?

Upgrade org.keycloak:keycloak-server-spi-private to 12.0.0 or later.

## Is CVE-2020-10776 being exploited?

There is no known exploitation of CVE-2020-10776 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-2020-10776 and fix it if it is affected.

What it is: CVE-2020-10776 is a medium-severity cross-site scripting vulnerability in Redhat Keycloak, published on 17 Nov 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-10776 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.keycloak:keycloak-server-spi-private (Maven): affected all versions; fixed in 12.0.0
- org.keycloak:keycloak-server-spi-private (Maven): affected all versions; fixed in 12.0.0
- org.keycloak:keycloak-services (Maven): affected all versions; fixed in 12.0.0
- org.keycloak:keycloak-services (Maven): affected all versions; fixed in 12.0.0

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-2020-10776/ (Markdown: https://insights.sbomify.com/CVE-2020-10776/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-10776
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-10776
- OSV: https://osv.dev/vulnerability/CVE-2020-10776

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-10776/
Summaries are generated and may contain mistakes; the official description above is the record.