PT-2023-7251 · Zyxel · Zyxel Usg Flex Series+3

Alessandro Sgreccia · Published 2023-08-17 · Updated 2023-12-04 · CVE-2023-4397

Positive Technologies (AI Summary)

CVSS v2.0

4.6

Medium

Base vector

AV:L/AC:L/Au:S/C:N/I:N/A:C

Name of the Vulnerable Software and Affected Versions Zyxel ATP series version 5.37 Zyxel USG FLEX series version 5.37 Zyxel USG FLEX 50(W) series version 5.37 Zyxel USG20(W)-VPN series version 5.37

Description A buffer overflow issue in the firmware could allow an authenticated local attacker with administrator privileges to cause denial-of-service conditions by executing a CLI command with crafted strings on an affected device. The exploitation of this issue may result in a denial-of-service condition.

Recommendations For Zyxel ATP series version 5.37, update the firmware to a version that addresses the buffer overflow issue. For Zyxel USG FLEX series version 5.37, update the firmware to a version that addresses the buffer overflow issue. For Zyxel USG FLEX 50(W) series version 5.37, update the firmware to a version that addresses the buffer overflow issue. For Zyxel USG20(W)-VPN series version 5.37, update the firmware to a version that addresses the buffer overflow issue. As a temporary workaround, consider restricting the execution of CLI commands with crafted strings on affected devices until a patch is available.

Fix

Buffer Overflow

Weakness Enumeration

CWE-119

CWE-120

Related Identifiers

BDU:2023-08279

CVE-2023-4397

Affected Products

Zyxel Atp Series

Zyxel Usg Flex 50(W) Series

Zyxel Usg Flex Series

Zyxel Usg20(W)-Vpn Series

References · 6

• https://bdu.fstec.ru/vul/2023-08279 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2023-4397 · Security Note
• https://zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2023-4397 · Vendor Advisory
• https://vuldb.com/?id.246233 · Note
• https://t.me/cvenotify/61295 · Telegram Post