CVE-2020-25014: Buffer Overflow

Published Nov 27, 2020
·
Updated

A stack-based buffer overflow in fbwificontinue.cgi on Zyxel UTM and VPN series of gateways running firmware version V4.30 through to V4.55 allows remote unauthenticated attackers to execute arbitrary code via a crafted http packet.

Affected Software

289 affected components
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel ZyWALL 110
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel ZyWALL 1100
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel ZyWALL 310
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 110
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 1100
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 1900
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 20w
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 20w-vpn
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 2200-vpn
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 310
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 40
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 40w
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 60
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg 60w
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG110
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG1100
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG1900
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG20-VPN
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG20W-VPN
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG210
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG2200-VPN
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG310
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG40
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG40W
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG60
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG60W
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Vpn100
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Vpn300
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Vpn50
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg Flex 100
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG FLEX 200
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG FLEX 500
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel Usg Flex 100w
All of the following
Zyxel ZLD>=4.30<=4.55
Zyxel USG FLEX 700
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa1123-ac Hd
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa1123-ac Pro
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa1123-acv2
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel WAX510D
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Wac5302d-s
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa5120
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa5301-nj
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Wax610d
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Wax650s
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Wac6550
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Wac6303d-s
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Wac6500
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Wac6100
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa210ax
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel NWA110AX
All of the following
Any of the following
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa1302-ac
Zyxel Zld Firmware>=4.30<=4.55
Zyxel ZyWALL 110
Zyxel ZyWALL 1100
Zyxel ZyWALL 310
Zyxel Usg 110
Zyxel Usg 1100
Zyxel Usg 1900
Zyxel Usg 20w
Zyxel Usg 20w-vpn
Zyxel Usg 2200-vpn
Zyxel Usg 310
Zyxel Usg 40
Zyxel Usg 40w
Zyxel Usg 60
Zyxel Usg 60w
Zyxel USG110
Zyxel USG1100
Zyxel USG1900
Zyxel USG20-VPN
Zyxel USG20W-VPN
Zyxel USG210
Zyxel USG2200-VPN
Zyxel USG310
Zyxel USG40
Zyxel USG40W
Zyxel USG60
Zyxel USG60W
Zyxel Vpn100
Zyxel Vpn300
Zyxel Vpn50
Zyxel Usg Flex 100
Zyxel USG FLEX 200
Zyxel USG FLEX 500
Zyxel Usg Flex 100w
Zyxel USG FLEX 700
Zyxel Access Points Firmware<=6.10
Zyxel Access Points Firmware=6.10
Zyxel Access Points Firmware=6.10-patch1
Zyxel Access Points Firmware=6.10-patch2
Zyxel Access Points Firmware=6.10-patch3
Zyxel Access Points Firmware=6.10-patch4
Zyxel Access Points Firmware=6.10-patch5
Zyxel Access Points Firmware=6.10-patch6
Zyxel Access Points Firmware=6.10-patch7
Zyxel Nwa1123-ac Hd
Zyxel Nwa1123-ac Pro
Zyxel Access Points Firmware
Zyxel Nwa1123-acv2
Zyxel WAX510D
Zyxel Wac5302d-s
Zyxel Nwa5120
Zyxel Nwa5301-nj
Zyxel Wax610d
Zyxel Wax650s
Zyxel Wac6550
Zyxel Wac6303d-s
Zyxel Wac6500
Zyxel Wac6100
Zyxel Nwa210ax
Zyxel NWA110AX
Zyxel Nwa1302-ac

Event History

Nov 27, 2020
CVE Published
via MITRE·05:18 PM
Data Sourced
via MITRE·05:18 PM
Description
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is CVE-2020-25014?

CVE-2020-25014 is a stack-based buffer overflow vulnerability found in the Zyxel UTM and VPN series of gateways firmware version V4.30 through to V4.55.

2

How severe is CVE-2020-25014?

CVE-2020-25014 has a severity rating of 9.8 (critical).

3

How can remote unauthenticated attackers exploit CVE-2020-25014?

Remote unauthenticated attackers can exploit CVE-2020-25014 by sending a crafted HTTP packet, which can allow them to execute arbitrary code.

4

Which Zyxel devices are affected by CVE-2020-25014?

Zyxel UTM and VPN series of gateways running firmware version V4.30 through to V4.55 are affected by CVE-2020-25014.

5

How can I fix CVE-2020-25014?

To fix CVE-2020-25014, Zyxel has released a security advisory and patches that should be applied to the affected devices. Please refer to the Zyxel support website for more information.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203