USG/ZyWALL series firmware: Improper Authentication
CVE-2022-0342 is a critical-severity improper authentication vulnerability in USG/ZyWALL series firmware from Zyxel, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected USG/ZyWALL series firmware versions: 4.20 through 4.70. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 95.1% chance of exploitation within 30 days, which is in the top 0.13% of all scored CVEs.
Exploitation in the next 30 days is more likely than not, according to EPSS.
What to do
- Update Usg40 Firmware to 4.71 or a later version.
- Update Usg40w Firmware to 4.71 or a later version.
- Update Usg60 Firmware to 4.71 or a later version.
- Read the advisory on zyxel.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Zyxel | USG/ZyWALL series firmware | 4.20 through 4.70 | Not stated |
| Zyxel | USG FLEX series firmware | 4.50 through 5.20 | Not stated |
| Zyxel | ATP series firmware | 4.32 through 5.20 | Not stated |
| Zyxel | VPN series firmware | 4.30 through 5.20 | Not stated |
| Zyxel | NSG series firmware | 1.20 through 1.33 Patch 4 | Not stated |
| Zyxel | Usg40 Firmware | 4.20 up to, but not including, 4.71 | 4.71 |
| Zyxel | Usg40w Firmware | 4.20 up to, but not including, 4.71 | 4.71 |
| Zyxel | Usg60 Firmware | 4.20 up to, but not including, 4.71 | 4.71 |
| Zyxel | Usg60w Firmware | 4.20 up to, but not including, 4.71 | 4.71 |
| Zyxel | Zywall 110 Firmware | 4.20 up to, but not including, 4.71 | 4.71 |
| Zyxel | Zywall 310 Firmware | 4.20 up to, but not including, 4.71 | 4.71 |
| Zyxel | Zywall 1100 Firmware | 4.20 up to, but not including, 4.71 | 4.71 |
| Zyxel | Usg Flex 100 Firmware | 4.50 through 5.20 | Not stated |
| Zyxel | Usg Flex 200 Firmware | 4.50 through 5.20 | Not stated |
| Zyxel | Usg Flex 500 Firmware | 4.50 through 5.20 | Not stated |
| Zyxel | Usg Flex 100w Firmware | 4.50 through 5.20 | Not stated |
| Zyxel | Usg Flex 700 Firmware | 4.50 through 5.20 | Not stated |
| Zyxel | Atp100 Firmware | 4.32 through 5.20 | Not stated |
| Zyxel | Atp100w Firmware | 4.32 through 5.20 | Not stated |
| Zyxel | Atp200 Firmware | 4.32 through 5.20 | Not stated |
| Zyxel | Atp500 Firmware | 4.32 through 5.20 | Not stated |
| Zyxel | Atp700 Firmware | 4.32 through 5.20 | Not stated |
| Zyxel | Atp800 Firmware | 4.32 through 5.20 | Not stated |
| Zyxel | Vpn50 Firmware | 4.30 up to, but not including, 5.21 | 5.21 |
| Zyxel | Vpn100 Firmware | 4.30 up to, but not including, 5.21 | 5.21 |
Version data comes from the organisation that assigned the CVE; 3 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA (zyxel.com.tw) |
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 2.0 | 7.5 | High | NVD |
Official description
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 series firmware versions 4.32 through 5.20, VPN series firmware versions 4.30 through 5.20, and NSG series firmware versions V1.20 through V1.33 Patch 4, which could allow an attacker to bypass the web authentication and obtain administrative access of the device.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in USG/ZyWALL series firmware
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Recent Improper Authentication vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.5 High severity
- 8.8 High severity
- 7.8 High severity
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