LTE3316-M604: Improper Access Control
CVE-2023-22920 is a critical-severity improper access control vulnerability in LTE3316-M604 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 LTE3316-M604 versions: V2.00(ABMP.6)C0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.84% chance of exploitation within 30 days, higher than 58% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of LTE3316-M604 you run against the affected versions below, and install the vendor's latest release.
- 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 | LTE3316-M604 | V2.00(ABMP.6)C0 | Not stated |
| Zyxel | Lte3202-m437 Firmware | 1.00\(abwf.1\)c0 | Not stated |
| Zyxel | Lte3316-m604 Firmware | 2.00\(abmp.6\)c0 | Not stated |
Version data comes from the organisation that assigned the CVE. 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 |
Official description
A security misconfiguration vulnerability exists in the Zyxel LTE3316-M604 firmware version V2.00(ABMP.6)C0 due to a factory default misconfiguration intended for testing purposes. A remote attacker could leverage this vulnerability to access an affected device using Telnet.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Recent Improper Access Control vulnerabilities
- 8.8 High severity
- 8.2 High severity
- 5.3 Medium severity
Joomla! Improper Access Control Exploited
- 8.8 High severity
- 9.8 Critical severity
- 7.8 High severity
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