# CVE-2017-6181: Denial of service in n/a

> Remote attackers can crash applications using the Onigmo library by submitting crafted regular expressions that trigger deep recursion.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** No
- **Published:** 3 Apr 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-5pfp-rwpx-xgfx

## What is CVE-2017-6181?

CVE-2017-6181 is a high-severity denial of service vulnerability in Ruby-Lang Ruby, published on 3 Apr 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The parse_char_class function in regparse.c in the Onigmo (aka Oniguruma-mod) regular expression library, as used in Ruby 2.4.0, allows remote attackers to cause a denial of service (deep recursion and application crash) via a crafted regular expression.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-6181?

It affects 1 product.


Products: Ruby-Lang Ruby.

## How do I fix CVE-2017-6181?

No fix has been published for CVE-2017-6181 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-6181 being exploited?

There is no known exploitation of CVE-2017-6181 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-2017-6181 and fix it if it is affected.

What it is: CVE-2017-6181 is a high-severity denial of service vulnerability in Ruby-Lang Ruby, published on 3 Apr 2017. 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-2017-6181 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-2017-6181/ (Markdown: https://insights.sbomify.com/CVE-2017-6181/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-6181
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-6181
- OSV: https://osv.dev/vulnerability/CVE-2017-6181

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-6181/
Summaries are generated and may contain mistakes; the official description above is the record.