# CVE-2018-12384: Weak cryptography in Network Security Services (NSS)

> NSS library fails to generate random values for SSLv2-compatible ClientHello requests, allowing full malleability of the handshake.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Apr 2019
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2018-12384, DEBIAN-CVE-2018-12384, GHSA-rg3c-6wcj-37gm, MGASA-2018-0393, RHSA-2018:2768, RHSA-2018:2898, UBUNTU-CVE-2018-12384

## What is CVE-2018-12384?

CVE-2018-12384 is a medium-severity vulnerability in Mozilla Network Security Services, published on 29 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When handling a SSLv2-compatible ClientHello request, the server doesn't generate a new random value but sends an all-zero value instead. This results in full malleability of the ClientHello for SSLv2 used for TLS 1.2 in all versions prior to NSS 3.39. This does not impact TLS 1.3.

Weakness: CWE-335 (Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG))

## Which versions are affected by CVE-2018-12384?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nss` | Red Hat:enterprise_linux:6::client | All versions | 0:3.36.0-9.el6_10 |
| `nss-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:3.36.0-9.el6_10 |
| `nss-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:3.36.0-9.el6_10 |
| `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:3.36.0-9.el6_10 |
| `nss-sysinit` | Red Hat:enterprise_linux:6::client | All versions | 0:3.36.0-9.el6_10 |
| `nss-tools` | Red Hat:enterprise_linux:6::client | All versions | 0:3.36.0-9.el6_10 |
| `nss` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.36.0-9.el6_10 |
| `nss-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.36.0-9.el6_10 |
| `nss-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.36.0-9.el6_10 |
| `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.36.0-9.el6_10 |
| `nss-sysinit` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.36.0-9.el6_10 |
| `nss-tools` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.36.0-9.el6_10 |
| `nss` | Red Hat:enterprise_linux:6::server | All versions | 0:3.36.0-9.el6_10 |
| `nss-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:3.36.0-9.el6_10 |
| `nss-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:3.36.0-9.el6_10 |
| `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:3.36.0-9.el6_10 |
| `nss-sysinit` | Red Hat:enterprise_linux:6::server | All versions | 0:3.36.0-9.el6_10 |
| `nss-tools` | Red Hat:enterprise_linux:6::server | All versions | 0:3.36.0-9.el6_10 |
| `nss` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.36.0-9.el6_10 |
| `nss-debuginfo` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.36.0-9.el6_10 |
| `nss-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.36.0-9.el6_10 |
| `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.36.0-9.el6_10 |
| `nss-sysinit` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.36.0-9.el6_10 |
| `nss-tools` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.36.0-9.el6_10 |
| `nss` | Red Hat:enterprise_linux:7::client | All versions | 0:3.36.0-7.el7_5 |
| `nss-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.36.0-7.el7_5 |
| `nss-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.36.0-7.el7_5 |
| `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.36.0-7.el7_5 |
| `nss-sysinit` | Red Hat:enterprise_linux:7::client | All versions | 0:3.36.0-7.el7_5 |
| `nss-tools` | Red Hat:enterprise_linux:7::client | All versions | 0:3.36.0-7.el7_5 |
| `nss` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.36.0-7.el7_5 |
| `nss-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.36.0-7.el7_5 |
| `nss-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.36.0-7.el7_5 |
| `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.36.0-7.el7_5 |
| `nss-sysinit` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.36.0-7.el7_5 |
| `nss-tools` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.36.0-7.el7_5 |
| `nss` | Red Hat:enterprise_linux:7::server | All versions | 0:3.36.0-7.el7_5 |
| `nss-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:3.36.0-7.el7_5 |
| `nss-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:3.36.0-7.el7_5 |
| `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:3.36.0-7.el7_5 |

Products: Mozilla Network Security Services.

## How do I fix CVE-2018-12384?

Upgrade to a fixed version.

## Is CVE-2018-12384 being exploited?

There is no known exploitation of CVE-2018-12384 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-2018-12384 and fix it if it is affected.

What it is: CVE-2018-12384 is a medium-severity vulnerability in Mozilla Network Security Services, published on 29 Apr 2019. 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-2018-12384 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-2018-12384/ (Markdown: https://insights.sbomify.com/CVE-2018-12384/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-12384
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-12384
- OSV: https://osv.dev/vulnerability/CVE-2018-12384

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-12384/
Summaries are generated and may contain mistakes; the official description above is the record.