# CVE-2023-1973: Undertow: unrestricted request storage leads to memory exhaustion

> Attackers can cause server memory exhaustion and denial of service by sending crafted requests to the Undertow web server.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Nov 2024
- **Updated:** 7 Nov 2024
- **Also known as:** DEBIAN-CVE-2023-1973, GHSA-97cq-f4jm-mv8h, OESA-2024-2419, UBUNTU-CVE-2023-1973

## What is CVE-2023-1973?

CVE-2023-1973 is a high-severity denial of service vulnerability in Red Hat JBoss Enterprise Application Platform 7, published on 7 Nov 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in Undertow package. Using the FormAuthenticationMechanism, a malicious user could trigger a Denial of Service by sending crafted requests, leading the server to an OutofMemory error, exhausting the server's memory.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2023-1973?

4 open source packages ship an affected version, including io.undertow:undertow-core.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `io.undertow:undertow-core` | Maven | All versions | 2.2.32.Final |
| `io.undertow:undertow-core` | Maven | All versions | 2.2.32.Final |
| `io.undertow:undertow-core` | Maven | From 2.3.0.Alpha1 | 2.3.13.Final |
| `io.undertow:undertow-core` | Maven | From 2.3.0.Alpha1 | 2.3.13.Final |

## How do I fix CVE-2023-1973?

Upgrade io.undertow:undertow-core to a fixed version for your release line: 2.2.32.Final or 2.3.13.Final.

## Is CVE-2023-1973 being exploited?

There is no known exploitation of CVE-2023-1973 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-1973 and fix it if it is affected.

What it is: CVE-2023-1973 is a high-severity denial of service vulnerability in Red Hat JBoss Enterprise Application Platform 7, published on 7 Nov 2024. 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-2023-1973 in the wild and no public exploit code.

Affected packages and fixed versions:
- io.undertow:undertow-core (Maven): affected all versions; fixed in 2.2.32.Final
- io.undertow:undertow-core (Maven): affected all versions; fixed in 2.2.32.Final
- io.undertow:undertow-core (Maven): affected from 2.3.0.Alpha1; fixed in 2.3.13.Final
- io.undertow:undertow-core (Maven): affected from 2.3.0.Alpha1; fixed in 2.3.13.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-2023-1973/ (Markdown: https://insights.sbomify.com/CVE-2023-1973/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-1973
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-1973
- OSV: https://osv.dev/vulnerability/CVE-2023-1973

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-1973/
Summaries are generated and may contain mistakes; the official description above is the record.