XSS in Mongo-Express

CVE-2021-21422

mongo-express is a web-based MongoDB admin interface, written with Node.js and express. 1: As mentioned in this issue: https://github.com/mongo-express/mongo-express/issues/577, when the content of a cell grows larger than supported size, clicking on a row will show full document unescaped, however this needs admin interaction on cell. 2: Data cells identified as media will be rendered as media, without being sanitized. Example of different renders: image, audio, video, etc. As an example of type 1 attack, an unauthorized user who only can send a large amount of data in a field of a document may use a payload with embedded javascript. This could send an export of a collection to the attacker without even an admin knowing. Other types of attacks such as dropping a database\collection are possible.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.016 (75.0th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 75.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-21422: held from 0.016 to 0.016.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-21422?
CVE-2021-21422 is a high-severity vulnerability in Mongo-Express, classified under Cross-site Scripting. CVSS score: 8.1/10. Published 2021-06-21.
How severe is CVE-2021-21422?
High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2021-21422 known to be exploited?
4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.