# CVE-2018-18508: Null dereference in NSS

> A malformed signature in Network Security Services causes a null dereference crash, leading to denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 22 Oct 2020
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-18508, GHSA-45r6-rwfw-29cq, UBUNTU-CVE-2018-18508, USN-3898-1

## What is CVE-2018-18508?

CVE-2018-18508 is a medium-severity vulnerability in Mozilla Network Security Services, published on 22 Oct 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

In Network Security Services (NSS) before 3.36.7 and before 3.41.1, a malformed signature can cause a crash due to a null dereference, resulting in a Denial of Service.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2018-18508?

It affects 9 products.


Products: Mozilla Network Security Services, Siemens Ruggedcom Rox Mx5000 Firmware, Siemens Ruggedcom Rox Rx1400 Firmware, Siemens Ruggedcom Rox Rx1500 Firmware, Siemens Ruggedcom Rox Rx1501 Firmware, Siemens Ruggedcom Rox Rx1510 Firmware, Siemens Ruggedcom Rox Rx1511 Firmware, Siemens Ruggedcom Rox Rx1512 Firmware, Siemens Ruggedcom Rox Rx5000 Firmware.

## How do I fix CVE-2018-18508?

Upgrade to a fixed version.

## Is CVE-2018-18508 being exploited?

There is no known exploitation of CVE-2018-18508 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Network Security Services

- [CVE-2019-17006](https://insights.sbomify.com/CVE-2019-17006/): Memory corruption in NSS (critical 9.8)
- [CVE-2017-5461](https://insights.sbomify.com/CVE-2017-5461/): Memory corruption in Firefox (critical 9.8)
- [CVE-2009-2404](https://insights.sbomify.com/CVE-2009-2404/): Memory corruption in n/a (critical 9.3)
- [CVE-2017-11695](https://insights.sbomify.com/CVE-2017-11695/): Memory corruption in n/a (high 7.8)
- [CVE-2017-11696](https://insights.sbomify.com/CVE-2017-11696/): Memory corruption in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-18508 and fix it if it is affected.

What it is: CVE-2018-18508 is a medium-severity vulnerability in Mozilla Network Security Services, published on 22 Oct 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-18508 in the wild and no public exploit code.

Affected product: Mozilla Network Security Services. 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-2018-18508/ (Markdown: https://insights.sbomify.com/CVE-2018-18508/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-18508
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-18508
- OSV: https://osv.dev/vulnerability/CVE-2018-18508

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-18508/
Summaries are generated and may contain mistakes; the official description above is the record.