A buffer overflow vulnerability in the “sdwan_iface_ipc” binary of Zyxel ATP series firmware versions 5.10 through 5.32, USG FLEX series firmware versions 5.00 through 5.32, USG FLEX 50(W) firmware versions 5.10 through 5.32, USG20(W)-VPN firmware versions 5.10 through 5.32, and VPN series firmware versions 5.00 through 5.35, which could allow a remote unauthenticated attacker to cause a core dump with a request error message on a vulnerable device by uploading a crafted configuration file.

The configuration parser of Zyxel ATP series firmware versions 5.10 through 5.35, USG FLEX series firmware versions 5.00 through 5.35, USG FLEX 50(W) firmware versions 5.10 through 5.35, USG20(W)-VPN firmware versions 5.10 through 5.35, and VPN series firmware versions 5.00 through 5.35, which fails to properly sanitize user input. A remote unauthenticated attacker could leverage the vulnerability to modify device configuration data, resulting in DoS conditions on an affected device if the attacker could trick an authorized administrator to switch the management mode to the cloud mode.

A buffer overflow vulnerability in the “fbwifi_forward.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.30 through 5.35, USG20(W)-VPN firmware versions 4.30 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote unauthenticated attacker to cause DoS conditions by sending a crafted HTTP request if the Facebook WiFi function were enabled on an affected device.

A path traversal vulnerability in the “account_print.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote authenticated attacker with administrator privileges to execute unauthorized OS commands in the “tmp” directory by uploading a crafted file if the hotspot function were enabled.

A post-authentication command injection vulnerability in the “account_operator.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote authenticated attacker to modify device configuration data, resulting in denial-of-service (DoS) conditions on an affected device.

A security misconfiguration vulnerability exists in the Zyxel LTE3316-M604 firmware version V2.00(ABMP.6)C0 due to a factory default misconfiguration intended for testing purposes. A remote attacker could leverage this vulnerability to access an affected device using Telnet.

An improper check for unusual conditions in Zyxel NWA110AX firmware verisons prior to 6.50(ABTG.0)C0, which could allow a LAN attacker to cause a temporary denial-of-service (DoS) by sending crafted VLAN frames if the MAC address of the vulnerable AP were intercepted by the attacker.

A cross-site scripting (XSS) vulnerability in Zyxel NBG-418N v2 firmware versions prior to V1.00(AARP.13)C0, which could allow an attacker to store malicious scripts in the Logs page of the GUI on a vulnerable device. A successful XSS attack could force an authenticated user to execute the stored malicious scripts and then result in a denial-of-service (DoS) condition when the user visits the Logs page of the GUI on the device.

A post-authentication command injection vulnerability in the CLI command of Zyxel ZyWALL/USG series firmware versions 4.20 through 4.72, VPN series firmware versions 4.30 through 5.32, USG FLEX series firmware versions 4.50 through 5.32, and ATP series firmware versions 4.32 through 5.32, which could allow an authenticated attacker with administrator privileges to execute OS commands.

A vulnerability exists in the FTP server of the Zyxel AX7501-B0 firmware prior to V5.17(ABPC.3)C0, which processes symbolic links on external storage media. A local authenticated attacker with administrator privileges could abuse this vulnerability to access the root file system by creating a symbolic link on external storage media, such as a USB flash drive, and then logging into the FTP server on a vulnerable device.