CVE-2023-33009

🗓️ 24 May 2023 00:00:00Reported by ZyxelType

CVE-2023-33009 Buffer overflow vulnerability in Zyxel ATP & USG FLEX series firmwar

Reporter	Title	Published	Views	Family All 26
ATTACKERKB	CVE-2023-33009	24 May 202313:15	–	attackerkb
BDU FSTEC	The vulnerability of the microprogrammed software of Zyxel ATP network devices, such as USG FLEX, USG FLEX50(W), USG20(W)-VPN, VPN, ZyWALL/USG, arises from copying buffers without checking the size of the input data. This allows a malicious actor to execute arbitrary code or cause service failures.	25 May 202300:00	–	bdu_fstec
Circl	CVE-2023-33009	24 May 202316:26	–	circl
CISA KEV Catalog	Zyxel Multiple Firewalls Buffer Overflow Vulnerability	5 Jun 202300:00	–	cisa_kev
CISA	CISA Adds Two Known Exploited Vulnerabilities to Catalog	5 Jun 202312:00	–	cisa
CNNVD	Zyxel ATP 安全漏洞	24 May 202300:00	–	cnnvd
Cvelist	CVE-2023-33009	24 May 202300:00	–	cvelist
EUVD	EUVD-2023-37198	3 Oct 202520:07	–	euvd
Malwarebytes	Zyxel patches two critical vulnerabilities	26 May 202315:00	–	malwarebytes
NCSC	Vulnerabilities fixed in Zyxel firewalls	25 May 202300:00	–	ncsc

NVD

Node

AND

zyxel atp100_firmwareRange4.60–5.36

zyxel atp100_firmwareMatch5.36-

zyxel atp100_firmwareMatch5.36patch1

zyxel atp100Match-

Node

AND

zyxel atp200_firmwareRange4.60–5.36

zyxel atp200_firmwareMatch5.36-

zyxel atp200_firmwareMatch5.36patch1

zyxel atp200Match-

Node

AND

zyxel atp500_firmwareRange4.60–5.36

zyxel atp500_firmwareMatch5.36-

zyxel atp500_firmwareMatch5.36patch1

zyxel atp500Match-

Node

AND

zyxel atp100w_firmwareRange4.60–5.36

zyxel atp100w_firmwareMatch5.36-

zyxel atp100w_firmwareMatch5.36patch1

zyxel atp100wMatch-

Node

AND

zyxel atp700_firmwareRange4.60–5.36

zyxel atp700_firmwareMatch5.36-

zyxel atp700_firmwareMatch5.36patch1

zyxel atp700Match-

Node

AND

zyxel atp800_firmwareRange4.60–5.36

zyxel atp800_firmwareMatch5.36-

zyxel atp800_firmwareMatch5.36patch1

zyxel atp800Match-

Node

AND

zyxel usg_flex_100_firmwareRange4.60–5.36

zyxel usg_flex_100_firmwareMatch5.36-

zyxel usg_flex_100_firmwareMatch5.36patch1

zyxel usg_flex_100Match-

Node

AND

zyxel usg_flex_50_firmwareRange4.60–5.36

zyxel usg_flex_50_firmwareMatch5.36-

zyxel usg_flex_50_firmwareMatch5.36patch1

zyxel usg_flex_50Match-

Node

AND

zyxel usg_flex_200_firmwareRange4.60–5.36

zyxel usg_flex_200_firmwareMatch5.36-

zyxel usg_flex_200_firmwareMatch5.36patch1

zyxel usg_flex_200Match-

Node

AND

zyxel usg_flex_500_firmwareRange4.60–5.36

zyxel usg_flex_500_firmwareMatch5.36-

zyxel usg_flex_500_firmwareMatch5.36patch1

zyxel usg_flex_500Match-

Node

AND

zyxel usg_flex_700_firmwareRange4.60–5.36

zyxel usg_flex_700_firmwareMatch5.36-

zyxel usg_flex_700_firmwareMatch5.36patch1

zyxel usg_flex_700Match-

Node

AND

zyxel usg_flex_100w_firmwareRange4.60–5.36

zyxel usg_flex_100w_firmwareMatch5.36-

zyxel usg_flex_100w_firmwareMatch5.36patch1

zyxel usg_flex_100wMatch-

Node

AND

zyxel usg_flex_50w_firmwareRange4.60–5.36

zyxel usg_flex_50w_firmwareMatch5.36-

zyxel usg_flex_50w_firmwareMatch5.36patch1

zyxel usg_flex_50wMatch-

Node

AND

zyxel usg_20w-vpn_firmwareRange4.60–5.36

zyxel usg_20w-vpn_firmwareMatch5.36-

zyxel usg_20w-vpn_firmwareMatch5.36patch1

zyxel usg_20w-vpnMatch-

Node

AND

zyxel vpn100_firmwareRange4.60–5.36

zyxel vpn100_firmwareMatch5.36-

zyxel vpn100_firmwareMatch5.36patch1

zyxel vpn100Match-

Node

AND

zyxel vpn50_firmwareRange4.60–5.36

zyxel vpn50_firmwareMatch5.36-

zyxel vpn50_firmwareMatch5.36patch1

zyxel vpn50Match-

Node

AND

zyxel vpn300_firmwareRange4.60–5.36

zyxel vpn300_firmwareMatch5.36-

zyxel vpn300_firmwareMatch5.36patch1

zyxel vpn300Match-

Node

AND

zyxel vpn1000_firmwareRange4.60–5.36

zyxel vpn1000_firmwareMatch5.36-

zyxel vpn1000_firmwareMatch5.36patch1

zyxel vpn1000Match-

Node

AND

zyxel usg20-vpn_firmwareRange4.60–5.36

zyxel usg20-vpn_firmwareMatch5.36-

zyxel usg20-vpn_firmwareMatch5.36patch1

zyxel usg20-vpnMatch-

Node

AND

zyxel usg_40_firmwareRange4.60–4.73

zyxel usg_40_firmwareMatch4.73-

zyxel usg_40_firmwareMatch4.73patch1

zyxel usg_40Match-

Node

AND

zyxel usg_40w_firmwareRange4.60–4.73

zyxel usg_40w_firmwareMatch4.73-

zyxel usg_40w_firmwareMatch4.73patch1

zyxel usg_40wMatch-

Node

AND

zyxel usg_60w_firmwareRange4.60–4.73

zyxel usg_60w_firmwareMatch4.73-

zyxel usg_60w_firmwareMatch4.73patch1

zyxel usg_60wMatch-

Node

AND

zyxel usg_60_firmwareRange4.60–4.73

zyxel usg_60_firmwareMatch4.73-

zyxel usg_60_firmwareMatch4.73patch1

zyxel usg_60Match-

[
  {
    "defaultStatus": "unaffected",
    "product": "ATP series firmware",
    "vendor": "Zyxel",
    "versions": [
      {
        "status": "affected",
        "version": "4.60 through 5.36 Patch 1"
      }
    ]
  },
  {
    "defaultStatus": "unaffected",
    "product": "USG FLEX series firmware",
    "vendor": "Zyxel",
    "versions": [
      {
        "status": "affected",
        "version": "4.60 through 5.36 Patch 1"
      }
    ]
  },
  {
    "defaultStatus": "unaffected",
    "product": "USG FLEX 50(W) firmware",
    "vendor": "Zyxel",
    "versions": [
      {
        "status": "affected",
        "version": "4.60 through 5.36 Patch 1"
      }
    ]
  },
  {
    "defaultStatus": "unaffected",
    "product": "USG20(W)-VPN firmware",
    "vendor": "Zyxel",
    "versions": [
      {
        "status": "affected",
        "version": "4.60 through 5.36 Patch 1"
      }
    ]
  },
  {
    "defaultStatus": "unaffected",
    "product": "VPN series firmware",
    "vendor": "Zyxel",
    "versions": [
      {
        "status": "affected",
        "version": "4.60 through 5.36 Patch 1"
      }
    ]
  },
  {
    "defaultStatus": "unaffected",
    "product": "ZyWALL/USG series firmware",
    "vendor": "Zyxel",
    "versions": [
      {
        "status": "affected",
        "version": "4.60 through 4.73 Patch 1"
      }
    ]
  }
]

Source	Link
zyxel	www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-buffer-overflow-vulnerabilities-of-firewalls
cisa	www.cisa.gov/known-exploited-vulnerabilities-catalog

17 Jun 2026 06:00Current

9.9High risk

Vulners AI Score9.9

CVSS 3.19.8

EPSS0.28144

SSVC