Auth bypass in Zyxel Nbg6818
CVE-2021-35033
A vulnerability in specific versions of Zyxel NBG6818, NBG7815, WSQ20, WSQ50, WSQ60, and WSR30 firmware with pre-configured password management could allow an attacker to obtain root access of the device, if the local attacker dismantles the device and uses a USB-to-UART cable to connect the device, or if the remote assistance feature had been enabled by an authenticated user.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (33.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Zyxel Nbg6818
- Zyxel Nbg6818 Firmware
- Zyxel Nbg6818 Series Firmware — versions 1.00(ABSC.0)C0 through 1.00(ABSC.4)C0
- Zyxel Nbg7815
- Zyxel Nbg7815 Firmware
- Zyxel Nbg7815 Series Firmware — versions 1.00(ABSK.0)C0 through 1.00(ABSK.6)C0
- Zyxel Wsq20
- Zyxel Wsq20 Firmware
- Zyxel Wsq20 Series Firmware — versions 1.00(ABOF.0)C0 through 1.00(ABOF.10)C0
- Zyxel Wsq50
Weakness classification (CWE)
References
- www.zyxel.com/support/Zyxel_security_advisory_for_pre-configured_password_manag… (Vendor Advisory)
- www.tenable.com/security/research/tra-2022-06 (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-35033?
- CVE-2021-35033 is a high-severity vulnerability in Zyxel Nbg6818, classified under CWE-260. CVSS score: 7.8/10. Published 2021-11-23.
- How severe is CVE-2021-35033?
- High severity. CVSS v3 base score is 7.8 out of 10.