Multiple vulnerabilitiesin Zyxel firewalls
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2023-27990 CVE-2023-27991 CVE-2023-28771 |
| CWE-ID | CWE-79 CWE-78 |
| Exploitation vector | Network |
| Public exploit | Vulnerability #3 is being exploited in the wild. |
| Vulnerable software Subscribe |
ATP series Hardware solutions / Routers for home users USG FLEX series Client/Desktop applications / Antivirus software/Personal firewalls VPN series Client/Desktop applications / Antivirus software/Personal firewalls USG series Client/Desktop applications / Antivirus software/Personal firewalls USG FLEX 50W Hardware solutions / Firmware USG20W-VPN Hardware solutions / Firmware ZyWALL Other software / Other software solutions |
| Vendor | ZyXEL Communications Corp. |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
1) Stored cross-site scripting
EUVDB-ID: #VU75459
Risk: Low
CVSSv3.1:
CVE-ID: CVE-2023-27990
CWE-ID:
Exploit availability:
DescriptionThe disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data. A remote user can inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
MitigationInstall update from vendor's website.
Vulnerable software versionsATP series: 4.32 - 5.35
USG FLEX series: 4.50 - 5.35
USG FLEX 50W: 4.16 - 5.35
USG20W-VPN: 4.16 - 5.35
VPN series: 4.30 - 5.35
Fixed software versionsCPE2.3 External links
Q & A
Can this vulnerability be exploited remotely?
How the attacker can exploit this vulnerability?
Is there known malware, which exploits this vulnerability?
2) OS Command Injection
EUVDB-ID: #VU75460
Risk: Medium
CVSSv3.1:
CVE-ID: CVE-2023-27991
CWE-ID:
Exploit availability:
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation. 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 update from vendor's website.
Vulnerable software versionsATP series: 4.32 - 5.35
USG FLEX series: 4.50 - 5.35
USG FLEX 50W: 4.16 - 5.35
USG20W-VPN: 4.16 - 5.35
VPN series: 4.30 - 5.35
Fixed software versionsCPE2.3 External links
Q & A
Can this vulnerability be exploited remotely?
How the attacker can exploit this vulnerability?
Is there known malware, which exploits this vulnerability?
3) OS Command Injection
EUVDB-ID: #VU75461
Risk: High
CVSSv3.1:
CVE-ID: CVE-2023-28771
CWE-ID:
Exploit availability:
DescriptionThe vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation. 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 versionsATP series: 4.60 - 5.35
USG FLEX series: 4.60 - 5.35
VPN series: 4.60 - 5.35
ZyWALL: 4.60 - 4.73
USG series: 4.60 - 4.73
Fixed software versionsCPE2.3 External links
http://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-remote-command-injection-vulnerability-of-firewalls
http://www.zyxel.com/global/en/support/security-advisories/zyxels-guidance-for-the-recent-attacks-on-the-zywall-devices
Q & A
Can this vulnerability be exploited remotely?
How the attacker can exploit this vulnerability?
Is there known malware, which exploits this vulnerability?
