CVE-2021-43787CWE-1321CWE-79

XSS via prototype pollution

Critical · published November 29, 2021

CVSS v3.1
9.0
EPSS
1%
Percentile
70.6
In the wild
Unconfirmed
What it is

🚨 A simple flaw in NodeBB's uploader module could let attackers inject malicious JavaScript straight into the forum's DOM! 🔥 Think of it like a restaurant where anyone can sneak a note onto the menu and rewrite the specials — if the kitchen doesn’t check it, diners could end up with something unsafe on their plate! If exploited, a malicious user could take control of accounts, manipulate data, or spread harmful scripts across the forum. This isn't just a security headache; it could lead to significant data breaches and loss of user trust! Don't let this happen to your community!

Put simply

Think of it like a restaurant where anyone can sneak a note onto the menu and rewrite the specials — if the kitchen doesn’t check it, diners could end up with something unsafe on their plate! This prototype pollution vulnerability in the uploader module of NodeBB allows attackers to inject arbitrary data, opening doors to potential account takeovers, especially when combined with a path traversal issue also reported at the same time.

What to do

If exploited, a malicious user could take control of accounts, manipulate data, or spread harmful scripts across the forum. This isn't just a security headache; it could lead to significant data breaches and loss of user trust! Don't let this happen to your community! To stay safe, upgrade NodeBB immediately to version 1.18.5 or later. Additionally, review your forum settings and reinforce security policies to prevent unauthorized access. Don't wait — this patch is essential! You can tackle this! Follow these steps, and you'll have your forum secure in no time! 🛡️

The record
Technical detail
CVSS v3.1
9.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.01317 · 70.6th percentile
Weaknesses
CWE-1321 · Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'); CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2021-11-29T19:30Z
EPSS history
Timeline
  • 29 NOV 19:30Z
    XSS via prototype pollution
    cvelistv5