CVE-2023-33009

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2023-06-05. Federal remediation due 2023-06-26.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

28.14% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 97.9% of scored records. A rank, not a probability.

NVD base score

9.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2023-05-24 00:00Z3 YR AGO

Last updated

2025-10-21 23:05Z1 YR AGO

Reserved

2023-05-17

Assigning CNA

Zyxel

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')Base

Data version

5.1

Document digest

8b31f492990810b2b1c5373216a7e73d6495a76b99dfabf9458fe7adecadeaf2

• www.zyxel.comhttps://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-buffer-overflow-vulnerabilities-of-firewalls
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-33009government-resource