CVE-2020-9054 on CISA KEV

Multiple 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 authent

01What CISA says about this vulnerability

Multiple 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…

02Required action — verbatim from CISA

Apply updates per vendor instructions.

03Notes & references

• cwe.mitre.org — https://cwe.mitre.org/data/definitions/78.html
• www.zyxel.com — https://www.zyxel.com/support/remote-code-execution-vulnerability-of-NAS-product…
• kb.cert.org — https://kb.cert.org/vuls/id/498544/
• kb.cert.org — https://kb.cert.org/artifacts/cve-2020-9054.html
• krebsonsecurity.com — https://krebsonsecurity.com/2020/02/zyxel-fixes-0day-in-network-storage-devices/

04SARA's analyst layer — why this matters

This vulnerability is currently on the CISA KEV list, which CISA only adds CVEs to when there is reliable evidence of active exploitation in the wild. For federal civilian agencies, BOD 22-01 requires remediation by the due date above. For everyone else, KEV is the strongest "patch immediately" signal you can get from public threat intel.

05Affected products (summary)

06Detection

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