# CVE-2021-3734: Improper Restriction of Rendered UI Layers or Frames in yourls

Source: https://junglewise.ai/threats/cve-2021-3734-improper-restriction-of-rendered-ui-layers-or-frames-in-yourls  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-08-30  
License: CC BY 4.0 with a link back

CVE-2021-3734 · Severity: low · CVSS 3 · Published 2021-08-30

Improper Restriction of Rendered UI Layers or Frames in yourls

Technologies: [yourls/yourls (Packagist)](https://junglewise.ai/threats/technologies/yourls-yourls). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2021-3734 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-3734 being exploited in the wild.

**How severe is CVE-2021-3734?** Low severity, with a CVSS score of 3, published 30 August 2021.

**Which products and versions are affected?** yourls/yourls (Packagist) ECOSYSTEM:introduced=0,last_affected=1.8.1.

**Is there a fix for CVE-2021-3734?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2021-3734?** Check whether you run yourls/yourls (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- yourls/yourls (Packagist) ECOSYSTEM:introduced=0,last_affected=1.8.1

## Identifiers

- CVE-2021-3734
- GHSA-r6g8-jmj9-g945

## Related threats

- [YOURLS unauthenticated path traversal file inclusion](https://junglewise.ai/threats/cve-2026-62858-yourls-unauthenticated-file-inclusion)
- [YOURLS stored XSS in referrer statistics via crafted Referer header](https://junglewise.ai/threats/cve-2026-63135-yourls-stored-xss-in-referrer-statistics-via-crafted-referer)
- [YOURLS is vulnerable to XSS through JSONP and Callback request parameters](https://junglewise.ai/threats/yourls-is-vulnerable-to-xss-through-jsonp-and-callback-request-d2d8fa38)
- [YOURLS Stored Cross Site Scripting (XSS)](https://junglewise.ai/threats/cve-2020-27388-yourls-stored-cross-site-scripting-xss)
- [Cross-Site Request Forgery in YOURLS](https://junglewise.ai/threats/cve-2022-0088-cross-site-request-forgery-in-yourls)