# CVE-2020-10687: HTTP Request Smuggling in Undertow

> An attacker can exploit HTTP request smuggling in Undertow to poison caches, perform XSS, or steal sensitive data from other users' requests.

- **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:** 23 Sep 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-10687, GHSA-p9w3-gwc2-cr49, UBUNTU-CVE-2020-10687

## What is CVE-2020-10687?

CVE-2020-10687 is a medium-severity vulnerability in Redhat Jboss Enterprise Application Platform, published on 23 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2020-10687?

2 open source packages ship an affected version, including io.undertow:undertow-core. It affects 3 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.undertow:undertow-core` | Maven | All versions | 2.2.0.Final |
| `io.undertow:undertow-core` | Maven | All versions | 2.2.0.Final |

Products: Redhat Jboss Enterprise Application Platform, Redhat Single Sign-On, Redhat Undertow.

## How do I fix CVE-2020-10687?

Upgrade io.undertow:undertow-core to 2.2.0.Final or later.

## Is CVE-2020-10687 being exploited?

There is no known exploitation of CVE-2020-10687 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Jboss Enterprise Application Platform

- [CVE-2017-12149](https://insights.sbomify.com/CVE-2017-12149/): Red Hat JBoss Application Server Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2010-1428](https://insights.sbomify.com/CVE-2010-1428/): Red Hat JBoss Information Disclosure (medium 5.9, exploited in the wild)
- [CVE-2010-0738](https://insights.sbomify.com/CVE-2010-0738/): Red Hat JBoss Authentication Bypass (low 3.7, exploited in the wild)
- [CVE-2016-3690](https://insights.sbomify.com/CVE-2016-3690/): Deserialization in n/a (critical 9.8)
- [CVE-2017-7504](https://insights.sbomify.com/CVE-2017-7504/): Deserialization in JBoss (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-10687 and fix it if it is affected.

What it is: CVE-2020-10687 is a medium-severity vulnerability in Redhat Jboss Enterprise Application Platform, published on 23 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-2020-10687 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.undertow:undertow-core (Maven): affected all versions; fixed in 2.2.0.Final
- io.undertow:undertow-core (Maven): affected all versions; fixed in 2.2.0.Final

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-2020-10687/ (Markdown: https://insights.sbomify.com/CVE-2020-10687/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-10687
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-10687
- OSV: https://osv.dev/vulnerability/CVE-2020-10687

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-10687/
Summaries are generated and may contain mistakes; the official description above is the record.