Critical severity · published Jul 2, 2021
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…
9.8
CVSS
2.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)2.3% · higher than 83% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
UF
Usg Flex 100 Firmware · Zyxel
4.35 through 5.01 · source: NVD
UF
Usg Flex 100w Firmware · Zyxel
4.35 through 5.01 · source: NVD
UF
Usg Flex 200 Firmware · Zyxel
4.35 through 5.01 · source: NVD
UF
Usg Flex 500 Firmware · Zyxel
4.35 through 5.01 · source: NVD
UF
Usg Flex 700 Firmware · Zyxel
4.35 through 5.01 · source: NVD
UF
Usg100 Firmware · Zyxel
4.35 through 4.64 · source: NVD
UF
Usg1000 Firmware · Zyxel
4.35 through 4.64 · source: NVD
UF
Usg110 Firmware · Zyxel
4.35 through 4.64 · source: NVD
UF
Usg1100 Firmware · Zyxel
4.35 through 4.64 · source: NVD
UF
Usg1900 Firmware · Zyxel
4.35 through 4.64 · source: NVD
UF
Usg20 Firmware · Zyxel
4.35 through 4.64 · source: NVD
UF
Usg20-vpn Firmware · Zyxel
4.35 through 5.01 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-35029
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-35029
Vendor Advisory
https://www.zyxel.com/support/Zyxel_security_advisory_for_attacks_against_security_appliances.shtml
More from Usg Flex 100 Firmware
9.8
CVE-2023-33009
Zyxel Multiple Firewalls Buffer Overflow Vulnerability
9.8
CVE-2023-33010
Zyxel Multiple Firewalls Buffer Overflow Vulnerability
9.8
CVE-2023-28771
Zyxel Multiple Firewalls OS Command Injection Vulnerability
9.8
CVE-2020-29583
Zyxel Multiple Products Use of Hard-Coded Credentials Vulnerability
9.8
CVE-2022-0342
An authentication bypass vulnerability in the CGI program of Zyxel USG/ZyWALL series firmware versions 4.20 through 4.70, USG FLEX series firmware versions 4.50 through 5.20, ATP…