# CVE-2020-2252: Improper Validation of Certificate with Host Mismatch in Jenkins Mailer Plugin

> The Jenkins Mailer Plugin fails to validate SMTP server hostnames, allowing attackers to bypass security controls or redirect traffic.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:H/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:** Yes
- **Published:** 16 Sep 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-6fr3-286q-q3cr

## What is CVE-2020-2252?

CVE-2020-2252 is a medium-severity server-side request forgery vulnerability in Jenkins Mailer Plugin, published on 16 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Jenkins Mailer Plugin 1.32 and earlier does not perform hostname validation when connecting to the configured SMTP server.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2020-2252?

6 open source packages ship an affected version, including org.jenkins-ci.plugins:mailer. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.jenkins-ci.plugins:mailer` | Maven | All versions | 1.29.1 |
| `org.jenkins-ci.plugins:mailer` | Maven | All versions | 1.29.1 |
| `org.jenkins-ci.plugins:mailer` | Maven | From 1.30 | 1.31.1 |
| `org.jenkins-ci.plugins:mailer` | Maven | From 1.30 | 1.31.1 |
| `org.jenkins-ci.plugins:mailer` | Maven | From 1.32 | 1.32.1 |
| `org.jenkins-ci.plugins:mailer` | Maven | From 1.32 | 1.32.1 |

Products: Jenkins Mailer.

## How do I fix CVE-2020-2252?

Upgrade org.jenkins-ci.plugins:mailer to a fixed version for your release line: 1.29.1, 1.31.1 or 1.32.1.

## Is CVE-2020-2252 being exploited?

There is no known exploitation of CVE-2020-2252 in the wild and no public exploit code.

## Other vulnerabilities in Jenkins Mailer Plugin

- [CVE-2018-8718](https://insights.sbomify.com/CVE-2018-8718/): Cross-Site Request Forgery in Jenkins Mailer Plugin (high 8.0)
- [CVE-2022-20613](https://insights.sbomify.com/CVE-2022-20613/): Cross-Site Request Forgery in Jenkins Mailer Plugin (medium 4.3)
- [CVE-2022-20614](https://insights.sbomify.com/CVE-2022-20614/): Incorrect Permission Assignment for Critical Resource in Jenkins Mailer Plugin (medium 4.3)
- [CVE-2017-2651](https://insights.sbomify.com/CVE-2017-2651/): Exposure of Sensitive Information to an Unauthorized Actor in Jenkins-mailer-plugin (low 3.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-2252 and fix it if it is affected.

What it is: CVE-2020-2252 is a medium-severity server-side request forgery vulnerability in Jenkins Mailer Plugin, published on 16 Sep 2020. 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-2020-2252 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.jenkins-ci.plugins:mailer (Maven): affected all versions; fixed in 1.29.1
- org.jenkins-ci.plugins:mailer (Maven): affected all versions; fixed in 1.29.1
- org.jenkins-ci.plugins:mailer (Maven): affected from 1.30; fixed in 1.31.1
- org.jenkins-ci.plugins:mailer (Maven): affected from 1.30; fixed in 1.31.1
- org.jenkins-ci.plugins:mailer (Maven): affected from 1.32; fixed in 1.32.1
- org.jenkins-ci.plugins:mailer (Maven): affected from 1.32; fixed in 1.32.1

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-2020-2252/ (Markdown: https://insights.sbomify.com/CVE-2020-2252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-2252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-2252
- OSV: https://osv.dev/vulnerability/CVE-2020-2252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-2252/
Summaries are generated and may contain mistakes; the official description above is the record.