Vulnerability identifier: #VU48673

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
VPN series
Client/Desktop applications / Antivirus software/Personal firewalls
USG series
Client/Desktop applications / Antivirus software/Personal firewalls
USG FLEX series
Client/Desktop applications / Antivirus software/Personal firewalls
Unified Pro series
Hardware solutions / Other hardware appliances
Unified series
Hardware solutions / Other hardware appliances
Standalone series
Hardware solutions / Other hardware appliances

Vendor: ZyXEL Communications Corp.

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in the "fbwifi_continue" CGI program. A remote attacker can trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

VPN series: 4.30 - 4.55

USG series: 4.30 - 4.55

USG FLEX series: 4.30 - 4.55

Unified Pro series: All versions

Unified series: All versions

Standalone series: All versions

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External links
http://www.zyxel.com/support/Zyxel-security-advisory-for-buffer-overflow-vulnerability.shtml

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.