An improper restriction of operations within the bounds of a memory buffer in the USB file-sharing handler of the Zyxel VMG8825-T50K firmware versions through 5.50(ABOM.8)C0 could allow an authenticated attacker with administrator privileges to cause potential memory corruptions, resulting in a thread crash on an affected device.

An improper restriction of operations within the bounds of a memory buffer in the MAC address parser of the Zyxel VMG8825-T50K firmware versions through 5.50(ABOM.8)C0 could allow an authenticated attacker with administrator privileges to cause potential memory corruptions, resulting in a thread crash on an affected device.

An improper restriction of operations within the bounds of a memory buffer in the IPv6 address parser of the Zyxel VMG8825-T50K firmware versions through 5.50(ABOM.8)C0 could allow an authenticated attacker with administrator privileges to cause potential memory corruptions, resulting in a thread crash on an affected device.

An improper restriction of operations within the bounds of a memory buffer in the parameter type parser of the Zyxel VMG8825-T50K firmware versions through 5.50(ABOM.8)C0 could allow an authenticated attacker with administrator privileges to cause potential memory corruptions, resulting in a thread crash on an affected device.

**UNSUPPORTED WHEN ASSIGNED** A command injection vulnerability in the export-cgi program of Zyxel NAS326 firmware versions through V5.21(AAZF.18)C0 and NAS542 firmware versions through V5.21(ABAG.15)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands by sending a crafted HTTP POST request.

An insufficient entropy vulnerability caused by the improper use of a randomness function with low entropy for web authentication tokens generation exists in the Zyxel GS1900-10HP firmware version V2.80(AAZI.0)C0. This vulnerability could allow a LAN-based attacker a slight chance to gain a valid session token if multiple authenticated sessions are alive.

The improper neutralization of special elements in the parameter "host" in the CGI program of Zyxel NWA1123ACv3 firmware version 6.70(ABVT.4) and earlier, WAC500 firmware version 6.70(ABVS.4) and earlier, WAX655E firmware version 7.00(ACDO.1) and earlier, WBE530 firmware version 7.00(ACLE.1) and earlier, and USG LITE 60AX firmware version V2.00(ACIP.2) could allow an unauthenticated attacker to execute OS commands by sending a crafted cookie to a vulnerable device.

A reflected cross-site scripting (XSS) vulnerability in the CGI program "dynamic_script.cgi" of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V4.16 through V5.38, and USG20(W)-VPN series firmware versions from V4.16 through V5.38 could allow an attacker to trick a user into visiting a crafted URL with the XSS payload. The attacker could obtain browser-based information if the malicious script is executed on the victim’s browser.

A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V4.60 through V5.38 and USG FLEX series firmware versions from V4.60 through V5.38 could allow an authenticated attacker with administrator privileges to execute some operating system (OS) commands on an affected device by executing a crafted CLI command.

A buffer overflow vulnerability in the CGI program of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V4.16 through V5.38, and USG20(W)-VPN series firmware versions from V4.16 through V5.38 could allow an authenticated attacker with administrator privileges to cause denial of service (DoS) conditions by sending a crafted HTTP request to a vulnerable device.