SARA / Free Tools / CVE / CVE-2023-28771

CVE-2023-28771 — Zyxel Multiple Firewalls OS Command Injection Vulnerability

Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG FLEX series firmware versions 4.60 through 5.35, and ATP series firmware versions 4.60 through 5.35, which could allow an unauthenti

CVSS
9.8 CRITICAL
EPSS
94.35% (top 0.00%)
CWE
CWE-78
Published
2023-04-25T00:00:00.000Z
Last modified
2025-10-21T23:05:48.400Z
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA KEV — Actively Exploited
Added to KEV
2023-05-31
BOD 22-01 due
2023-06-21
Ransomware use
Unknown

01What is this vulnerability?

Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG FLEX series firmware versions 4.60 through 5.35, and ATP series firmware versions 4.60 through 5.35, which could allow an unauthenticated attacker to execute some OS commands remotely by sending crafted packets to an affected device.

02Affected products

VendorProductVersions
ZyxelZyWALL/USG series firmware4.60 through 4.73
ZyxelVPN series firmware4.60 through 5.35
ZyxelUSG FLEX series firmware4.60 through 5.35
ZyxelATP series firmware4.60 through 5.35

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2023-05-31. Ransomware use: Unknown.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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