CVE-2023-27991 : The post-authentication command injection vulnerability in the CLI command of Zy

The post-authentication command injection vulnerability in the CLI command of Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker to execute some OS commands remotely.

Published 2023-04-24 18:15:09

Updated 2023-06-13 13:18:20

Source Zyxel Corporation

View at NVD, CVE.org

Products affected by CVE-2023-27991

Zyxel » Usg 20w-vpn Firmware
Versions from including (>=) 4.16 and before (<) 5.36
cpe:2.3:o:zyxel:usg_20w-vpn_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg 20w-vpn » Version: N/A
Zyxel » Atp200 Firmware
Versions from including (>=) 4.32 and before (<) 5.36
cpe:2.3:o:zyxel:atp200_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Atp200 » Version: N/A
Zyxel » Atp500 Firmware
Versions from including (>=) 4.32 and before (<) 5.36
cpe:2.3:o:zyxel:atp500_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Atp500 » Version: N/A
Zyxel » Atp800 Firmware
Versions from including (>=) 4.32 and before (<) 5.36
cpe:2.3:o:zyxel:atp800_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Atp800 » Version: N/A
Zyxel » Usg20-vpn Firmware
Versions from including (>=) 4.30 and before (<) 5.36
cpe:2.3:o:zyxel:usg20-vpn_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg20-vpn » Version: N/A
Zyxel » Vpn50 Firmware
Versions from including (>=) 4.30 and before (<) 5.36
cpe:2.3:o:zyxel:vpn50_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Vpn50 » Version: N/A
Zyxel » Vpn100 Firmware
Versions from including (>=) 4.30 and before (<) 5.36
cpe:2.3:o:zyxel:vpn100_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Vpn100 » Version: N/A
Zyxel » Vpn300 Firmware
Versions from including (>=) 4.30 and before (<) 5.36
cpe:2.3:o:zyxel:vpn300_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Vpn300 » Version: N/A
Zyxel » Atp100 Firmware
Versions from including (>=) 4.32 and before (<) 5.36
cpe:2.3:o:zyxel:atp100_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Atp100 » Version: N/A
Zyxel » Vpn1000 Firmware
Versions from including (>=) 4.30 and before (<) 5.36
cpe:2.3:o:zyxel:vpn1000_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Vpn1000 » Version: N/A
Zyxel » Usg Flex 100 Firmware
Versions from including (>=) 4.50 and before (<) 5.36
cpe:2.3:o:zyxel:usg_flex_100_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg Flex 100 » Version: N/A
Zyxel » Usg Flex 200 Firmware
Versions from including (>=) 4.50 and before (<) 5.36
cpe:2.3:o:zyxel:usg_flex_200_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg Flex 200 » Version: N/A
Zyxel » Usg Flex 500 Firmware
Versions from including (>=) 4.50 and before (<) 5.36
cpe:2.3:o:zyxel:usg_flex_500_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg Flex 500 » Version: N/A
Zyxel » Usg Flex 100w Firmware
Versions from including (>=) 4.50 and before (<) 5.36
cpe:2.3:o:zyxel:usg_flex_100w_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg Flex 100w » Version: N/A
Zyxel » Usg Flex 700 Firmware
Versions from including (>=) 4.50 and before (<) 5.36
cpe:2.3:o:zyxel:usg_flex_700_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg Flex 700 » Version: N/A
Zyxel » Atp100w Firmware
Versions from including (>=) 4.32 and before (<) 5.36
cpe:2.3:o:zyxel:atp100w_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Atp100w » Version: N/A
Zyxel » Atp700 Firmware
Versions from including (>=) 4.32 and before (<) 5.36
cpe:2.3:o:zyxel:atp700_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Atp700 » Version: N/A
Zyxel » Usg Flex 50w Firmware
Versions from including (>=) 4.16 and before (<) 5.36
cpe:2.3:o:zyxel:usg_flex_50w_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg Flex 50w » Version: N/A
Zyxel » Usg Flex 50 Firmware
Versions from including (>=) 4.50 and before (<) 5.36
cpe:2.3:o:zyxel:usg_flex_50_firmware:*:*:*:*:*:*:*:*
Matching versions
When used together with: Zyxel » Usg Flex 50 » Version: N/A

Exploit prediction scoring system (EPSS) score for CVE-2023-27991

EPSS FAQ

1.03%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 76 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2023-27991

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
8.8	HIGH	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	2.8	5.9	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: Low User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: High
8.8	HIGH	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	2.8	5.9	Zyxel Corporation
Attack Vector: Network Attack Complexity: Low Privileges Required: Low User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: High

CWE ids for CVE-2023-27991

CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
Assigned by:
- nvd@nist.gov (Primary)
- security@zyxel.com.tw (Secondary)

References for CVE-2023-27991

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-xss-vulnerability-and-post-authentication-command-injection-vulnerability-in-firewalls

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Vulnerability Details : CVE-2023-27991

Products affected by CVE-2023-27991

Exploit prediction scoring system (EPSS) score for CVE-2023-27991

CVSS scores for CVE-2023-27991

CWE ids for CVE-2023-27991

References for CVE-2023-27991