© 2026 vulntracker.io

CVE-2023-22913

HIGH

8.1

CVSS Score

Published: April 24, 2023 at 12:00 AM UTC

Updated: June 17, 2026 at 05:36 AM UTC

24 products affected across 1 vendorUsg Flex 100W FirmwareUSG FLEX 200 firmwareUSG FLEX 700 firmware

Using USG FLEX series firmware by Zyxel?

Get instant alerts when new vulnerabilities affect USG FLEX series firmware - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

HIGH8.1

Exploit prediction

EPSS 1%

SSVC

No known exploit

Description

A post-authentication command injection vulnerability in the “account_operator.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote authenticated attacker to modify device configuration data, resulting in denial-of-service (DoS) conditions on an affected device.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Usg Flex 100 Firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-usg-flex-100 (same device)

Usg Flex 100W Firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-usg-flex-100w (same device)

USG FLEX 200 firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-usg-flex-200 (same device)

Usg Flex 50 Firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-usg-flex-50 (same device)

USG FLEX 500 firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-usg-flex-500 (same device)

Usg Flex 50W Firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

USG FLEX 700 firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-usg-flex-700 (same device)

VPN100 Firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-vpn100 (same device)

VPN1000 Firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-vpn1000 (same device)

VPN300 Firmware · Zyxel

95%

4.50 ≤ v ≤ 5.35

zyxel-vpn300 (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-of-firewalls-and-aps

References (1)

Vendor Advisory

Source: [email protected]

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-of-firewalls-and-aps

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHZyxel

Attack Vector: NETWORK
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-77

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create account Sign in

Free plan, no card