# CVE-2018-3840: Null dereference in Pixar Renderman

> An attacker can cause a denial of service in Pixar Renderman IT Display Service by sending a malformed network packet that triggers a null pointer dereference.

- **Severity:** Medium 5.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Jun 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-f4qg-fj27-xc48

## What is CVE-2018-3840?

CVE-2018-3840 is a medium-severity vulnerability in Talos Pixar Renderman, published on 26 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A denial-of-service vulnerability exists in the Pixar Renderman IT Display Service 21.6 (0x67). The vulnerability is present in the parsing of a network packet without proper validation of the packet. The data read by the application is not validated, and its use can lead to a null pointer dereference. The IT application is opened by a user and then listens for a connection on port 4001. An attacker can deliver an attack once the application has been opened.

Weakness: CWE-476 (NULL Pointer Dereference), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-3840?

It affects 1 product.


Products: Pixar Renderman.

## How do I fix CVE-2018-3840?

No fix has been published for CVE-2018-3840 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-3840 being exploited?

There is no known exploitation of CVE-2018-3840 in the wild and no public exploit code.

## Other vulnerabilities in Talos Pixar Renderman

- [CVE-2018-4054](https://insights.sbomify.com/CVE-2018-4054/): Privilege escalation in Pixar Renderman (critical 9.0)
- [CVE-2019-5015](https://insights.sbomify.com/CVE-2019-5015/): Privilege escalation in Pixar Renderman (critical 9.0)
- [CVE-2018-4055](https://insights.sbomify.com/CVE-2018-4055/): Privilege escalation in Pixar Renderman (high 7.1)
- [CVE-2018-3841](https://insights.sbomify.com/CVE-2018-3841/): Null dereference in Pixar Renderman (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-3840 and fix it if it is affected.

What it is: CVE-2018-3840 is a medium-severity vulnerability in Talos Pixar Renderman, published on 26 Jun 2018. 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-2018-3840 in the wild and no public exploit code.

Affected product: Talos Pixar Renderman. 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-2018-3840/ (Markdown: https://insights.sbomify.com/CVE-2018-3840/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-3840
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-3840
- OSV: https://osv.dev/vulnerability/CVE-2018-3840

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-3840/
Summaries are generated and may contain mistakes; the official description above is the record.