Description
A command injection vulnerability in the IPSec VPN feature 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 unauthenticated attacker to execute some OS commands on an affected device by sending a crafted username to the vulnerable device. Note that this attack could be successful only if the device was configured in User-Based-PSK authentication mode and a valid user with a long username exceeding 28 characters exists.
CVSS breakdown
CVSS 3.1
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected products
- Zyxel / ATP series firmwareversions V4.32 through V5.38 – versions V4.32 through V5.38
- Zyxel / USG20(W)-VPN series firmwareversions V4.16 through V5.38 – versions V4.16 through V5.38
- Zyxel / USG FLEX 50(W) series firmwareversions V4.16 through V5.38 – versions V4.16 through V5.38
- Zyxel / USG FLEX series firmwareversions V4.50 through V5.38 – versions V4.50 through V5.38