Auth bypass in Mercari

CVE-2021-20835

Improper authorization in handler for custom URL scheme vulnerability in Android App 'Mercari (Merpay) - Marketplace and Mobile Payments App' (Japan version) versions prior to 4.49.1 allows a remote attacker to lead a user to access an arbitrary website and the website launches an arbitrary Activity of the app via the vulnerable App, which may result in Mercari account's access token being obtained.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.016 (75.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 75.2% 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-2021-20835: held from 0.016 to 0.016.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-20835?
CVE-2021-20835 is a high-severity vulnerability in Mercari, classified under Missing Authorization. CVSS score: 7.5/10. Published 2021-11-24.
How severe is CVE-2021-20835?
High severity. CVSS v3 base score is 7.5 out of 10.