# CVE-2023-26436: Deserialization in OX App Suite

> Attackers with local network access to the documentconverterws API can inject serialized Java objects to execute arbitrary code.

- **Severity:** High 7.1 (`CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Jun 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-5xxc-86g5-876q

## What is CVE-2023-26436?

CVE-2023-26436 is a high-severity unsafe deserialization vulnerability in OX App Suite, published on 20 Jun 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Attackers with access to the "documentconverterws" API were able to inject serialized Java objects, that were not properly checked during deserialization. Access to this API endpoint is restricted to local networks by default. Arbitrary code could be injected that is being executed when processing the request. A check has been introduced to restrict processing of legal and expected classes for this API. We now log a warning in case there are attempts to inject illegal classes. No publicly available exploits are known.

Weakness: CWE-502 (Deserialization of Untrusted Data), CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2023-26436?

It affects 1 product.


Products: Open-Xchange Open-Xchange Appsuite Backend.

## How do I fix CVE-2023-26436?

No fix has been published for CVE-2023-26436 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-26436 being exploited?

There is no known exploitation of CVE-2023-26436 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-2023-26428](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)
- [CVE-2023-26435](https://insights.sbomify.com/CVE-2023-26435/): Server-side request forgery in OX App Suite (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-26436 and fix it if it is affected.

What it is: CVE-2023-26436 is a high-severity unsafe deserialization vulnerability in OX App Suite, published on 20 Jun 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-26436 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-2023-26436/ (Markdown: https://insights.sbomify.com/CVE-2023-26436/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-26436
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-26436
- OSV: https://osv.dev/vulnerability/CVE-2023-26436

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-26436/
Summaries are generated and may contain mistakes; the official description above is the record.