PT-2021-20317 · Npm · Ansi Up

Published 2021-03-05 · Updated 2025-11-03 · CVE-2021-3377

Positive Technologies (AI Summary)

CVSS v3.1

6.1

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions: ansi up versions prior to 5.0.0

Description: The npm package ansi up is affected by a cross-site scripting (XSS) vulnerability due to insufficient URL sanitization when converting ANSI escape codes into HTML. This issue allows ANSI escape codes to create HTML hyperlinks.

Recommendations: For versions prior to 5.0.0, update to version 5.0.0 to resolve the issue. As a temporary workaround, consider disabling the feature that allows ANSI escape codes to create HTML hyperlinks until the update is applied.

Exploit

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2021-3377

GHSA-2V5F-23XC-V9QR

Affected Products

Ansi Up

References · 13

• 🔥 https://doyensec.com/resources/Doyensec_Advisory_ansi_up4_XSS.pdf · Exploit
• https://github.com/drudru/ansi_up/commit/c8c726ed1db979bae4f257b7fa41775155ba2e27 · Patch
• https://ubuntu.com/security/CVE-2021-3377 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-3377 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-3377 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-3377 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-3377 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-2v5f-23xc-v9qr · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-3377 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-3377 · Vendor Advisory
• https://t.me/cvenotify/10972 · Telegram Post
• https://t.me/cveNotify/141451 · Telegram Post
• https://security.netapp.com/advisory/ntap-20241108-0002 · Note