# CVE-2016-9643: Denial of service in n/a

> Remote attackers can cause a denial of service via memory consumption in WebKit's regex code using crafted input.

- **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:** Yes
- **Published:** 7 Mar 2017
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-4mcp-j554-p27j, UBUNTU-CVE-2016-9643

## What is CVE-2016-9643?

CVE-2016-9643 is a high-severity denial of service vulnerability in n/a, published on 7 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The regex code in Webkit 2.4.11 allows remote attackers to cause a denial of service (memory consumption) as demonstrated in a large number of ($ (open parenthesis and dollar) followed by {-2,16} and a large number of +) (plus close parenthesis).

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2016-9643?

It affects 1 product.


Products: Webkit Webkit.

## How do I fix CVE-2016-9643?

Apply the vendor's patch.

## Is CVE-2016-9643 being exploited?

There is no known exploitation of CVE-2016-9643 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2016-9642](https://insights.sbomify.com/CVE-2016-9642/): Memory corruption in n/a (medium 5.5)
- [CVE-2009-3933](https://insights.sbomify.com/CVE-2009-3933/): Denial of service in n/a (medium 5.0)
- [CVE-2008-6059](https://insights.sbomify.com/CVE-2008-6059/): Information disclosure in n/a (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9643 and fix it if it is affected.

What it is: CVE-2016-9643 is a high-severity denial of service vulnerability in n/a, published on 7 Mar 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-2016-9643 in the wild and no public exploit code.

Affected product: n/a. 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-2016-9643/ (Markdown: https://insights.sbomify.com/CVE-2016-9643/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9643
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9643
- OSV: https://osv.dev/vulnerability/CVE-2016-9643

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-9643/
Summaries are generated and may contain mistakes; the official description above is the record.