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 “sdwanifaceipc” 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 fails to sanitize user-controlled input in the Zyxel ATP series firmware versions 5.10 through 5.36, USG FLEX series firmware versions 5.00 through 5.36,  USG FLEX 50(W) series firmware versions 5.10 through 5.36,

USG20(W)-VPN series firmware versions 5.10 through 5.36, and VPN series firmware versions 5.00 through 5.36. An unauthenticated, LAN-based attacker could leverage the vulnerability to inject some operating system (OS) commands into the device configuration data on an affected device when the cloud management mode is enabled.