Vulnerability Intelligence Report
CVE-2023-27991
The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker to execute some OS commands remotely.
No Active Exploit Signals
CVSS Base Score
8.8
HIGH
Exploitability:2.9
Impact Score:5.9
EPSS Probability:1.51%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-78 ↗CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Zyxel | ATP series firmware | 4.32 through 5.35 (affected) |
| Zyxel | USG FLEX series firmware | 4.50 through 5.35 (affected) |
| Zyxel | USG FLEX 50(W) firmware | 4.16 through 5.35 (affected) |
| Zyxel | USG20(W)-VPN firmware | 4.16 through 5.35 (affected) |
| Zyxel | VPN series firmware | 4.30 through 5.35 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
EPSS Score
1.508%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Zyxel Corporation · Vendor · Taiwan |
| Reserved | 2023-03-09T00:00:00 |
| Published | 2023-04-24T00:00:00 |
| Last Updated | 2025-02-04T16:47:55 |
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