CVE-2020-9054

Summary

CVECVE-2020-9054
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2020-03-04 20:15:00 UTC
Updated2020-03-06 17:58:00 UTC
DescriptionMultiple ZyXEL network-attached storage (NAS) devices running firmware version 5.21 contain a pre-authentication command injection vulnerability, which may allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable device. ZyXEL NAS devices achieve authentication by using the weblogin.cgi CGI executable. This program fails to properly sanitize the username parameter that is passed to it. If the username parameter contains certain characters, it can allow command injection with the privileges of the web server that runs on the ZyXEL device. Although the web server does not run as the root user, ZyXEL devices include a setuid utility that can be leveraged to run any command with root privileges. As such, it should be assumed that exploitation of this vulnerability can lead to remote code execution with root privileges. By sending a specially-crafted HTTP POST or GET request to a vulnerable ZyXEL device, a remote, unauthenticated attacker may be able to execute arbitrary code on the device. This may happen by directly connecting to a device if it is directly exposed to an attacker. However, there are ways to trigger such crafted requests even if an attacker does not have direct connectivity to a vulnerable devices. For example, simply visiting a website can result in the compromise of any ZyXEL device that is reachable from the client system. Affected products include: NAS326 before firmware V5.21(AAZF.7)C0 NAS520 before firmware V5.21(AASZ.3)C0 NAS540 before firmware V5.21(AATB.4)C0 NAS542 before firmware V5.21(ABAG.4)C0 ZyXEL has made firmware updates available for NAS326, NAS520, NAS540, and NAS542 devices. Affected models that are end-of-support: NSA210, NSA220, NSA220+, NSA221, NSA310, NSA310S, NSA320, NSA320S, NSA325 and NSA325v2

Risk And Classification

EPSS: 0.943120000 probability, percentile 0.999480000 (date 2026-04-01)

CISA KEV: Listed on 2022-03-25; due 2022-04-15; ransomware use Unknown

Problem Types: CWE-78

CISA Known Exploited Vulnerability

VendorZyxel
ProductMultiple Network-Attached Storage (NAS) Devices
NameZyxel Multiple NAS Devices OS Command Injection Vulnerability
Required ActionApply updates per vendor instructions.
Noteshttps://nvd.nist.gov/vuln/detail/CVE-2020-9054

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Hardware Zyxel Atp100 - All All All
Hardware Zyxel Atp100 - All All All
Operating System Zyxel Atp100 Firmware All All All All
Operating System Zyxel Atp100 Firmware All All All All
Hardware Zyxel Atp200 - All All All
Hardware Zyxel Atp200 - All All All
Operating System Zyxel Atp200 Firmware All All All All
Operating System Zyxel Atp200 Firmware All All All All
Hardware Zyxel Atp500 - All All All
Hardware Zyxel Atp500 - All All All
Operating System Zyxel Atp500 Firmware All All All All
Operating System Zyxel Atp500 Firmware All All All All
Hardware Zyxel Atp800 - All All All
Hardware Zyxel Atp800 - All All All
Operating System Zyxel Atp800 Firmware All All All All
Operating System Zyxel Atp800 Firmware All All All All
Hardware Zyxel Nas326 - All All All
Hardware Zyxel Nas326 - All All All
Operating System Zyxel Nas326 Firmware All All All All
Operating System Zyxel Nas326 Firmware All All All All
Hardware Zyxel Nas520 - All All All
Hardware Zyxel Nas520 - All All All
Operating System Zyxel Nas520 Firmware All All All All
Operating System Zyxel Nas520 Firmware All All All All
Hardware Zyxel Nas540 - All All All
Hardware Zyxel Nas540 - All All All
Operating System Zyxel Nas540 Firmware All All All All
Operating System Zyxel Nas540 Firmware All All All All
Hardware Zyxel Nas542 - All All All
Hardware Zyxel Nas542 - All All All
Operating System Zyxel Nas542 Firmware All All All All
Operating System Zyxel Nas542 Firmware All All All All
Hardware Zyxel Usg110 - All All All
Hardware Zyxel Usg110 - All All All
Hardware Zyxel Usg1100 - All All All
Hardware Zyxel Usg1100 - All All All
Operating System Zyxel Usg1100 Firmware All All All All
Operating System Zyxel Usg1100 Firmware All All All All
Operating System Zyxel Usg110 Firmware All All All All
Operating System Zyxel Usg110 Firmware All All All All
Hardware Zyxel Usg1900 - All All All
Hardware Zyxel Usg1900 - All All All
Operating System Zyxel Usg1900 Firmware All All All All
Operating System Zyxel Usg1900 Firmware All All All All
Hardware Zyxel Usg20-vpn - All All All
Hardware Zyxel Usg20-vpn - All All All
Operating System Zyxel Usg20-vpn Firmware All All All All
Operating System Zyxel Usg20-vpn Firmware All All All All
Hardware Zyxel Usg20w-vpn - All All All
Hardware Zyxel Usg20w-vpn - All All All
Operating System Zyxel Usg20w-vpn Firmware All All All All
Operating System Zyxel Usg20w-vpn Firmware All All All All
Hardware Zyxel Usg210 - All All All
Hardware Zyxel Usg210 - All All All
Operating System Zyxel Usg210 Firmware All All All All
Operating System Zyxel Usg210 Firmware All All All All
Hardware Zyxel Usg2200 - All All All
Hardware Zyxel Usg2200 - All All All
Operating System Zyxel Usg2200 Firmware All All All All
Operating System Zyxel Usg2200 Firmware All All All All
Hardware Zyxel Usg310 - All All All
Hardware Zyxel Usg310 - All All All
Operating System Zyxel Usg310 Firmware All All All All
Operating System Zyxel Usg310 Firmware All All All All
Hardware Zyxel Usg40 - All All All
Hardware Zyxel Usg40 - All All All
Hardware Zyxel Usg40w - All All All
Hardware Zyxel Usg40w - All All All
Operating System Zyxel Usg40w Firmware All All All All
Operating System Zyxel Usg40w Firmware All All All All
Operating System Zyxel Usg40 Firmware All All All All
Operating System Zyxel Usg40 Firmware All All All All
Hardware Zyxel Usg60 - All All All
Hardware Zyxel Usg60 - All All All
Hardware Zyxel Usg60w - All All All
Hardware Zyxel Usg60w - All All All
Operating System Zyxel Usg60w Firmware All All All All
Operating System Zyxel Usg60w Firmware All All All All
Operating System Zyxel Usg60 Firmware All All All All
Operating System Zyxel Usg60 Firmware All All All All
Hardware Zyxel Vpn100 - All All All
Hardware Zyxel Vpn100 - All All All
Hardware Zyxel Vpn1000 - All All All
Hardware Zyxel Vpn1000 - All All All
Operating System Zyxel Vpn1000 Firmware All All All All
Operating System Zyxel Vpn1000 Firmware All All All All
Operating System Zyxel Vpn100 Firmware All All All All
Operating System Zyxel Vpn100 Firmware All All All All
Hardware Zyxel Vpn300 - All All All
Hardware Zyxel Vpn300 - All All All
Operating System Zyxel Vpn300 Firmware All All All All
Operating System Zyxel Vpn300 Firmware All All All All
Hardware Zyxel Vpn50 - All All All
Hardware Zyxel Vpn50 - All All All
Operating System Zyxel Vpn50 Firmware All All All All
Operating System Zyxel Vpn50 Firmware All All All All
Hardware Zyxel Zywall110 - All All All
Hardware Zyxel Zywall110 - All All All
Hardware Zyxel Zywall1100 - All All All
Hardware Zyxel Zywall1100 - All All All
Operating System Zyxel Zywall1100 Firmware All All All All
Operating System Zyxel Zywall1100 Firmware All All All All
Operating System Zyxel Zywall110 Firmware All All All All
Operating System Zyxel Zywall110 Firmware All All All All
Hardware Zyxel Zywall310 - All All All
Hardware Zyxel Zywall310 - All All All
Operating System Zyxel Zywall310 Firmware All All All All
Operating System Zyxel Zywall310 Firmware All All All All

References

ReferenceSourceLinkTags
kb.cert.org/artifacts/cve-2020-9054.html MISC kb.cert.org Third Party Advisory, US Government Resource
Zyxel Fixes 0day in Network Storage Devices — Krebs on Security MISC krebsonsecurity.com Exploit, Third Party Advisory
Zyxel security advisory for the remote code execution vulnerability of NAS and firewall products | Zyxel CONFIRM www.zyxel.com Vendor Advisory
CWE - CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') (4.9) MISC cwe.mitre.org Third Party Advisory
VU#498544 - ZyXEL pre-authentication command injection in weblogin.cgi CERT-VN kb.cert.org Third Party Advisory, US Government Resource
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
CISA Known Exploited Vulnerabilities catalog CISA www.cisa.gov kev

Vendor Comments And Credit

Discovery Credit

LEGACY: Thanks to Alex Holden of Hold Security for finding and reporting this vulnerability.

Legacy QID Mappings

  • 731233 Zyxel Network Attached Storage (NAS) and Firewall Remote Code Execution (RCE) Vulnerability
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