CVE-2021-3377 ansi_up cross-site scripting vulnerability
An attacker can inject malicious scripts via ANSI escape codes in the ansi_up library, leading to cross-site scripting attacks.
- 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
What is CVE-2021-3377?
CVE-2021-3377 is a medium-severity cross-site scripting vulnerability in n/a, published on 5 Mar 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
The npm package ansi_up converts ANSI escape codes into HTML. In ansi_up v4, ANSI escape codes can be used to create HTML hyperlinks. Due to insufficient URL sanitization, this feature is affected by a cross-site scripting (XSS) vulnerability. This issue is fixed in v5.0.0.
Weakness: CWE-79
Which versions are affected by CVE-2021-3377?
2 open source packages ship an affected version, including ansi_up. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
ansi_up npm | All versions | 5.0.0 |
ansi_up npm | All versions | 5.0.0 |
Products include Ansi Up Project Ansi Up.
How do I fix CVE-2021-3377?
Upgrade ansi_up to 5.0.0 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-2021-3377 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-3377 exists.
Public exploit code: 1 Nuclei template.
Sources
Also known as DEBIAN-CVE-2021-3377, GHSA-2v5f-23xc-v9qr, UBUNTU-CVE-2021-3377.