Auth bypass in Zyxel Atp Series Firmware

CVE-2021-35029

An authentication bypasss vulnerability in the web-based management interface of Zyxel USG/Zywall series firmware versions 4.35 through 4.64 and USG Flex, ATP, and VPN series firmware versions 4.35 through 5.01, which could allow a remote attacker to execute arbitrary commands on an affected device.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.023 (82.8th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 83rd percentile — 82.8% 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-2021-35029: held from 0.023 to 0.023.

EPSS over last 30 days · oldest: 0.023 · newest: 0.023 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-35029?
CVE-2021-35029 is a critical-severity vulnerability in Zyxel Atp Series Firmware, classified under Improper Authentication. CVSS score: 9.8/10. Published 2021-07-02.
How severe is CVE-2021-35029?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-35029 known to be exploited?
4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.