# CVE-2023-26432: Denial of service in OX App Suite

> An attacker with a rogue SMTP service can cause denial of service in OX App Suite by sending excessively large SMTP capability responses.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Jun 2023
- **Updated:** 3 Dec 2024
- **Also known as:** GHSA-9628-xx9p-xjqj

## What is CVE-2023-26432?

CVE-2023-26432 is a medium-severity denial of service vulnerability in OX App Suite, published on 20 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

When adding an external mail account, processing of SMTP "capabilities" responses are not limited to plausible sizes. Attacker with access to a rogue SMTP service could trigger requests that lead to excessive resource usage and eventually service unavailability. We now limit accepted SMTP server response to reasonable length/size. No publicly available exploits are known.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2023-26432?

It affects 1 product.


Products: Open-Xchange Open-Xchange Appsuite Backend.

## How do I fix CVE-2023-26432?

No fix has been published for CVE-2023-26432 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-26432 being exploited?

There is no known exploitation of CVE-2023-26432 in the wild and no public exploit code.

## Other vulnerabilities in OX App Suite

- [CVE-2023-26451](https://insights.sbomify.com/CVE-2023-26451/): Weak cryptography in OX App Suite (high 7.5)
- [CVE-2023-26436](https://insights.sbomify.com/CVE-2023-26436/): Deserialization in OX App Suite (high 7.1)
- [CVE-2023-26428](https://insights.sbomify.com/CVE-2023-26428/): Missing authorization in OX App Suite (medium 6.5)
- [CVE-2023-26443](https://insights.sbomify.com/CVE-2023-26443/): SQL injection in OX App Suite (medium 5.5)
- [CVE-2023-26431](https://insights.sbomify.com/CVE-2023-26431/): Server-side request forgery in OX App Suite (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26432 and fix it if it is affected.

What it is: CVE-2023-26432 is a medium-severity denial of service vulnerability in OX App Suite, published on 20 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-26432 in the wild and no public exploit code.

Affected product: OX App Suite. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2023-26432/ (Markdown: https://insights.sbomify.com/CVE-2023-26432/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26432
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26432
- OSV: https://osv.dev/vulnerability/CVE-2023-26432

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26432/
Summaries are generated and may contain mistakes; the official description above is the record.