# CVE-2021-26272: Inclusion of Functionality from Untrusted Control Sphere in CKEditor 4

> Attackers can cause a denial of service in CKEditor by tricking users into pasting crafted text that triggers excessive processing in the Autolink plugin.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 26 Jan 2021
- **Updated:** 3 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-26272, GHSA-wpvm-wqr4-p7cw, UBUNTU-CVE-2021-26272

## What is CVE-2021-26272?

CVE-2021-26272 is a medium-severity denial of service vulnerability in Oracle Agile Product Lifecycle Management, published on 26 Jan 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted URL-like text into the editor, and then press Enter or Space (in the Autolink plugin).

Weakness: CWE-829 (Inclusion of Functionality from Untrusted Control Sphere)

## Which versions are affected by CVE-2021-26272?

2 open source packages ship an affected version, including ckeditor4. It affects 10 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ckeditor4` | npm | All versions | 4.16.0 |
| `ckeditor4` | npm | All versions | 4.16.0 |

Products: Ckeditor Ckeditor, Oracle Agile Product Lifecycle Management, Oracle Application Express, Oracle Banking Party Management, Oracle Commerce Merchandising, Oracle Financial Services Analytical Applications Infrastructure, Oracle Financial Services Model Management and Governance, Oracle Jd Edwards Enterpriseone Tools, Oracle Siebel Ui Framework, Oracle Webcenter Sites.

## How do I fix CVE-2021-26272?

Upgrade ckeditor4 to 4.16.0 or later.

## Is CVE-2021-26272 being exploited?

There is no known exploitation of CVE-2021-26272 in the wild and no public exploit code.

## Other vulnerabilities in Oracle Agile Product Lifecycle Management

- [CVE-2023-31541](https://insights.sbomify.com/CVE-2023-31541/): File upload in n/a (critical 9.8)
- [CVE-2021-41164](https://insights.sbomify.com/CVE-2021-41164/): Advanced Content Filter (ACF) vulnerability allowing to execute JavaScript code using malformed HTML (high 8.2)
- [CVE-2021-41165](https://insights.sbomify.com/CVE-2021-41165/): HTML comments vulnerability allowing to execute JavaScript code (high 8.2)
- [CVE-2021-32808](https://insights.sbomify.com/CVE-2021-32808/): Cross-site scripting in ckeditor via abuse of undo functionality (high 7.6)
- [CVE-2011-4972](https://insights.sbomify.com/CVE-2011-4972/): Missing authorization in CKEditor Drupal module (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-26272 and fix it if it is affected.

What it is: CVE-2021-26272 is a medium-severity denial of service vulnerability in Oracle Agile Product Lifecycle Management, published on 26 Jan 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-26272 in the wild and no public exploit code.

Affected packages and fixed versions:
- ckeditor4 (npm): affected all versions; fixed in 4.16.0
- ckeditor4 (npm): affected all versions; fixed in 4.16.0

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-2021-26272/ (Markdown: https://insights.sbomify.com/CVE-2021-26272/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-26272
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-26272
- OSV: https://osv.dev/vulnerability/CVE-2021-26272

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-26272/
Summaries are generated and may contain mistakes; the official description above is the record.