# CVE-2018-0737: Cache timing vulnerability in RSA Key Generation

> An attacker with local access can recover RSA private keys via cache timing side-channel attacks during key generation in OpenSSL.

- **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:** 16 Apr 2018
- **Updated:** 15 Oct 2026
- **Also known as:** ALPINE-CVE-2018-0737, DEBIAN-CVE-2018-0737, GHSA-rj52-j648-hww8, SUSE-SU-2018:2486-1, SUSE-SU-2018:2492-1, SUSE-SU-2018:2928-1, SUSE-SU-2018:2928-2, SUSE-SU-2019:0197-1, UBUNTU-CVE-2018-0737, USN-3628-1, openSUSE-SU-2019:0152-1

## What is CVE-2018-0737?

CVE-2018-0737 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 16 Apr 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The OpenSSL RSA Key generation algorithm has been shown to be vulnerable to a cache timing side channel attack. An attacker with sufficient access to mount cache timing attacks during the RSA key generation process could recover the private key. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2b-1.0.2o).

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2018-0737?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `openssl` | SUSE:Enterprise Storage 4 | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:Linux Enterprise Desktop 12 SP3 | All versions | 1.0.2j-60.39.1 |
| `openssl-1_1` | SUSE:Linux Enterprise Module for Basesystem 15 | All versions | 1.1.0i-4.18.1 |
| `openssl` | SUSE:Linux Enterprise Server 11 SP4 | All versions | 0.9.8j-0.106.15.1 |
| `openssl` | SUSE:Linux Enterprise Server 12 SP1-LTSS | All versions | 1.0.1i-54.17.1 |
| `openssl` | SUSE:Linux Enterprise Server 12 SP2-BCL | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:Linux Enterprise Server 12 SP2-LTSS | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:Linux Enterprise Server 12 SP3 | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:Linux Enterprise Server for SAP Applications 11 SP4 | All versions | 0.9.8j-0.106.15.1 |
| `openssl` | SUSE:Linux Enterprise Server for SAP Applications 12 SP1 | All versions | 1.0.1i-54.17.1 |
| `openssl` | SUSE:Linux Enterprise Server for SAP Applications 12 SP2 | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:Linux Enterprise Software Development Kit 11 SP4 | All versions | 0.9.8j-0.106.15.1 |
| `openssl` | SUSE:Linux Enterprise Software Development Kit 12 SP3 | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:OpenStack Cloud 7 | All versions | 1.0.2j-60.39.1 |
| `openssl` | SUSE:Studio Onsite 1.3 | All versions | 0.9.8j-0.106.15.1 |
| `openssl-1_1` | openSUSE:Leap 15.0 | All versions | 1.1.0i-lp150.3.18.1 |

Products: Canonical Ubuntu Linux, Openssl Openssl.

## How do I fix CVE-2018-0737?

Upgrade to a fixed version.

## Is CVE-2018-0737 being exploited?

There is no known exploitation of CVE-2018-0737 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0737 and fix it if it is affected.

What it is: CVE-2018-0737 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 16 Apr 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-2018-0737 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. 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-2018-0737/ (Markdown: https://insights.sbomify.com/CVE-2018-0737/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0737
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0737
- OSV: https://osv.dev/vulnerability/CVE-2018-0737

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0737/
Summaries are generated and may contain mistakes; the official description above is the record.