PT-2023-2852 · Zyxel · Zyxel Usg20(W)-Vpn+5
Atdog
+1
·
Published
2023-05-24
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Updated
2025-09-17
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CVE-2023-33009
CVSS v3.1
10
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
Zyxel ATP series firmware versions 4.32 through 5.36 Patch 1
Zyxel USG FLEX series firmware versions 4.50 through 5.36 Patch 1
Zyxel USG FLEX 50(W) firmware versions 4.25 through 5.36 Patch 1
Zyxel USG20(W)-VPN firmware versions 4.25 through 5.36 Patch 1
Zyxel VPN series firmware versions 4.30 through 5.36 Patch 1
Zyxel ZyWALL/USG series firmware versions 4.25 through 4.73 Patch 1
Description
A buffer overflow vulnerability in the notification function could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions and even a remote code execution on an affected device. The vulnerability is related to a lack of size checking for input data, which can be exploited by a remote attacker.
Recommendations
For Zyxel ATP series firmware versions 4.32 through 5.36 Patch 1, update to a version later than 5.36 Patch 1.
For Zyxel USG FLEX series firmware versions 4.50 through 5.36 Patch 1, update to a version later than 5.36 Patch 1.
For Zyxel USG FLEX 50(W) firmware versions 4.25 through 5.36 Patch 1, update to a version later than 5.36 Patch 1.
For Zyxel USG20(W)-VPN firmware versions 4.25 through 5.36 Patch 1, update to a version later than 5.36 Patch 1.
For Zyxel VPN series firmware versions 4.30 through 5.36 Patch 1, update to a version later than 5.36 Patch 1.
For Zyxel ZyWALL/USG series firmware versions 4.25 through 4.73 Patch 1, update to a version later than 4.73 Patch 1.
As a temporary workaround, consider disabling the notification function until a patch is available.
Fix
Buffer Overflow
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Weakness Enumeration
Related Identifiers
Affected Products
Zyxel Atp Series
Zyxel Usg Flex 50
Zyxel Usg Flex Series
Zyxel Usg20(W)-Vpn
Zyxel Vpn Series
Zyxel Usg/Zywall Series