# CVE-2011-2686: Weak cryptography in n/a

> Attackers can predict random numbers in forked Ruby processes due to improper seed resetting, potentially compromising cryptographic operations.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:P/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:** 5 Aug 2011
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-g8g6-3p4h-6388

## What is CVE-2011-2686?

CVE-2011-2686 is a medium-severity vulnerability in Ruby-Lang Ruby, published on 5 Aug 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Ruby before 1.8.7-p352 does not reset the random seed upon forking, which makes it easier for context-dependent attackers to predict the values of random numbers by leveraging knowledge of the number sequence obtained in a different child process, a related issue to CVE-2003-0900.  NOTE: this issue exists because of a regression during Ruby 1.8.6 development.

Weakness: CWE-310

## Which versions are affected by CVE-2011-2686?

It affects 1 product.


Products: Ruby-Lang Ruby.

## How do I fix CVE-2011-2686?

Upgrade to a fixed version.

## Is CVE-2011-2686 being exploited?

There is no known exploitation of CVE-2011-2686 in the wild and no public exploit code.

## Other vulnerabilities in Ruby-Lang Ruby

- [CVE-2009-4124](https://insights.sbomify.com/CVE-2009-4124/): Memory corruption in n/a (critical 10.0)
- [CVE-2022-28738](https://insights.sbomify.com/CVE-2022-28738/): Use after free in n/a (critical 9.8)
- [CVE-2011-4121](https://insights.sbomify.com/CVE-2011-4121/): Weak cryptography in OpenSSL extension of Ruby (Git trunk) (critical 9.8)
- [CVE-2017-17790](https://insights.sbomify.com/CVE-2017-17790/): Command injection in n/a (critical 9.8)
- [CVE-2017-11465](https://insights.sbomify.com/CVE-2017-11465/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-2686 and fix it if it is affected.

What it is: CVE-2011-2686 is a medium-severity vulnerability in Ruby-Lang Ruby, published on 5 Aug 2011. 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-2011-2686 in the wild and no public exploit code.

Affected product: Ruby-Lang Ruby. 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-2011-2686/ (Markdown: https://insights.sbomify.com/CVE-2011-2686/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-2686
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-2686
- OSV: https://osv.dev/vulnerability/CVE-2011-2686

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-2686/
Summaries are generated and may contain mistakes; the official description above is the record.