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.
This vulnerability carries a CRITICAL severity rating with a CVSS v3.1 score of 9.8, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 74 products from zyxel, from zyxel, from zyxel and 71 others, organizations running these solutions should prioritize assessment and patching.
Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2021-07-02T11:15:08.930
2024-11-21T06:11:42.280
Modified
CVSSv3.1: 9.8 (CRITICAL)
AV:N/AC:L/Au:N/C:P/I:P/A:P
10.0
6.4
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | zyxel | usg1900_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg1900 | - | No |
| Operating System | zyxel | usg1100_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg1100 | - | No |
| Operating System | zyxel | usg310_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg310 | - | No |
| Operating System | zyxel | usg210_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg210 | - | No |
| Operating System | zyxel | usg110_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg110 | - | No |
| Operating System | zyxel | usg40_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg40 | - | No |
| Operating System | zyxel | usg40w_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg40w | - | No |
| Operating System | zyxel | usg60_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg60 | - | No |
| Operating System | zyxel | usg60w_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg60w | - | No |
| Operating System | zyxel | usg300_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg300 | - | No |
| Operating System | zyxel | usg1000_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg1000 | - | No |
| Operating System | zyxel | usg2000_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg2000 | - | No |
| Operating System | zyxel | usg20_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg20 | - | No |
| Operating System | zyxel | usg20w_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg20w | - | No |
| Operating System | zyxel | usg50_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg50 | - | No |
| Operating System | zyxel | usg100_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg100 | - | No |
| Operating System | zyxel | usg200_firmware | ≤ 4.64 | Yes |
| Hardware | zyxel | usg200 | - | No |
| Operating System | zyxel | usg_flex_100_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg_flex_100 | - | No |
| Operating System | zyxel | usg_flex_200_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg_flex_200 | - | No |
| Operating System | zyxel | usg_flex_500_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg_flex_500 | - | No |
| Operating System | zyxel | usg_flex_100w_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg_flex_100w | - | No |
| Operating System | zyxel | usg_flex_700_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg_flex_700 | - | No |
| Operating System | zyxel | zywall_atp100_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_atp100 | - | No |
| Operating System | zyxel | zywall_atp100w_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_atp100w | - | No |
| Operating System | zyxel | zywall_atp200_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_atp200 | - | No |
| Operating System | zyxel | zywall_atp500_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_atp500 | - | No |
| Operating System | zyxel | zywall_atp700_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_atp700 | - | No |
| Operating System | zyxel | zywall_atp800_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_atp800 | - | No |
| Operating System | zyxel | zywall_vpn50_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_vpn50 | - | No |
| Operating System | zyxel | zywall_vpn100_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_vpn100 | - | No |
| Operating System | zyxel | zywall_vpn300_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_vpn300 | - | No |
| Operating System | zyxel | usg20-vpn_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg20-vpn | - | No |
| Operating System | zyxel | usg20w-vpn_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg20w-vpn | - | No |
| Operating System | zyxel | usg2200-vpn_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | usg2200-vpn | - | No |
| Operating System | zyxel | zywall_110_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_110 | - | No |
| Operating System | zyxel | zywall_310_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_310 | - | No |
| Operating System | zyxel | zywall_1100_firmware | ≤ 5.01 | Yes |
| Hardware | zyxel | zywall_1100 | - | No |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For zyxel's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.