Multiple vulnerabilities in Zyxel NAS products
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 6 |
| CVE-ID | CVE-2023-35137 CVE-2023-35138 CVE-2023-37927 CVE-2023-37928 CVE-2023-4473 CVE-2023-4474 |
| CWE-ID | CWE-287 CWE-78 CWE-74 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
NAS326 Hardware solutions / Routers for home users NAS542 Hardware solutions / Routers for home users |
| Vendor | ZyXEL Communications Corp. |
Security Bulletin
This security bulletin contains information about 6 vulnerabilities.
1) Improper Authentication
EUVDB-ID: #VU83594
Risk: Medium
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-35137
CWE-ID:
CWE-287 - Improper Authentication
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to bypass authentication process.
The vulnerability exists due to an error in when processing authentication requests in the authentication module. A remote attacker can send a specially crafted URL to the target device and obtain system information.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNAS326: 5.21(AAZF.14)C0
NAS542: 5.21(ABAG.11)C0
External linksQ & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) OS Command Injection
EUVDB-ID: #VU83596
Risk: High
CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-35138
CWE-ID:
CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation in the "show_zysync_server_contents" function. A remote unauthenticated attacker can pass specially crafted data to the application and execute arbitrary OS commands on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNAS326: 5.21(AAZF.14)C0
NAS542: 5.21(ABAG.11)C0
External linksQ & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Improper Neutralization of Special Elements in Output Used by a Downstream Component
EUVDB-ID: #VU83597
Risk: Medium
CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-37927
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper neutralization of special elements in the CGI program. A remote user can pass specially crafted data to the application and execute arbitrary OS commands on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNAS326: 5.21(AAZF.14)C0
NAS542: 5.21(ABAG.11)C0
External linksQ & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
4) OS Command Injection
EUVDB-ID: #VU83598
Risk: Medium
CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-37928
CWE-ID:
CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation in the WSGI server. A remote user can pass specially crafted data to the application and execute arbitrary OS commands on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNAS326: 5.21(AAZF.14)C0
NAS542: 5.21(ABAG.11)C0
External linksQ & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
5) OS Command Injection
EUVDB-ID: #VU83599
Risk: High
CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-4473
CWE-ID:
CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation in the web server. A remote unauthenticated attacker can pass specially crafted data to the application and execute arbitrary OS commands on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNAS326: 5.21(AAZF.14)C0
NAS542: 5.21(ABAG.11)C0
External linksQ & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
6) Improper Neutralization of Special Elements in Output Used by a Downstream Component
EUVDB-ID: #VU83600
Risk: High
CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2023-4474
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper neutralization of special elements in the WSGI server. A remote user can pass specially crafted data to the application and execute arbitrary OS commands on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
MitigationInstall updates from vendor's website.
Vulnerable software versionsNAS326: 5.21(AAZF.14)C0
NAS542: 5.21(ABAG.11)C0
External linksQ & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
