CVE-2021-3785 Cross-site Scripting (XSS) - Stored in yourls/yourls
An attacker can inject malicious scripts into the Yourls URL shortener, potentially executing code or hijacking user sessions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-3785?
CVE-2021-3785 is a high-severity cross-site scripting vulnerability in yourls/yourls, published on 15 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
yourls is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Weakness: CWE-79
Which versions are affected by CVE-2021-3785?
2 open source packages ship an affected version, including yourls/yourls. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
yourls/yourls Packagist | All versions | 1.8.2 |
yourls/yourls Packagist | All versions | 1.8.2 |
Products include Yourls Yourls.
How do I fix CVE-2021-3785?
Upgrade yourls/yourls to 1.8.2 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-3785 being exploited?
There is no known exploitation of CVE-2021-3785 in the wild and no public exploit code.
Other vulnerabilities in yourls/yourls
- CVE-2019-14537 Access of Resource Using Incompatible Type ('Type Confusion') in yourls/yourls
- CVE-2021-3783 Cross-site Scripting (XSS) - Reflected in yourls/yourls
- CVE-2021-3734 Improper Restriction of Rendered UI Layers or Frames in yourls/yourls
- CVE-2020-27388 YOURLS Stored Cross Site Scripting (XSS)
- CVE-2011-3824 Information disclosure in n/a
Sources
Also known as GHSA-m9fq-c9hp-59g7.