# CVE-2020-2096: Reflected XSS vulnerability in Jenkins gitlab-hook Plugin

> Reflected XSS in Jenkins Gitlab Hook Plugin allows attackers to execute arbitrary scripts in victim browsers via unescaped project names.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Jan 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-8696-836p-c8qp

## What is CVE-2020-2096?

CVE-2020-2096 is a medium-severity cross-site scripting vulnerability in Jenkins Gitlab Hook Plugin, published on 15 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Jenkins Gitlab Hook Plugin 1.4.2 and earlier does not escape project names in the build_now endpoint, resulting in a reflected XSS vulnerability.

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

## Which versions are affected by CVE-2020-2096?

2 open source packages ship an affected version, including org.jenkins-ci.ruby-plugins:gitlab-hook. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.jenkins-ci.ruby-plugins:gitlab-hook` | Maven | All versions to 1.4.2 | None |
| `org.jenkins-ci.ruby-plugins:gitlab-hook` | Maven | All versions to 1.4.2 | None |

Products: Jenkins Gitlab Hook.

## How do I fix CVE-2020-2096?

No fix has been published for CVE-2020-2096 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-2096 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-2096 exists.

Public exploit code:

- Jenkins Gitlab Hook Plugin 1.4.2 - Reflected Cross-Site Scripting (exploitdb)
- Jenkins Gitlab Hook <=1.4.2 - Cross-Site Scripting (nuclei): http/cves/2020/CVE-2020-2096.yaml

## Other vulnerabilities in Jenkins Gitlab Hook Plugin

- [CVE-2018-1000196](https://insights.sbomify.com/CVE-2018-1000196/): Jenkins Gitlab Hook Plugin stores and displays GitLab API token in plain text (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-2096 and fix it if it is affected.

What it is: CVE-2020-2096 is a medium-severity cross-site scripting vulnerability in Jenkins Gitlab Hook Plugin, published on 15 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-2096 exists.

Affected packages and fixed versions:
- org.jenkins-ci.ruby-plugins:gitlab-hook (Maven): affected all versions up to 1.4.2; no fix listed
- org.jenkins-ci.ruby-plugins:gitlab-hook (Maven): affected all versions up to 1.4.2; 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-2020-2096/ (Markdown: https://insights.sbomify.com/CVE-2020-2096/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-2096
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-2096
- OSV: https://osv.dev/vulnerability/CVE-2020-2096

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-2096/
Summaries are generated and may contain mistakes; the official description above is the record.