CVE-2023-35138
9.8
CRITICAL · CVSS 3.1 · EPSS 40% (pctl 99)
Patch early
EPSS 40% — above the 10% action threshold.
Description
A command injection vulnerability in the “show_zysync_server_contents” function of the Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands by sending a crafted HTTP POST request.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 40% — more likely to be exploited than 99% of all CVEs |
| Weakness | CWE-78 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2023-11-30 |
| Last modified | 2026-06-17 |
Affected (4)
| Vendor | Product |
|---|---|
| zyxel | nas326 |
| zyxel | nas326 firmware |
| zyxel | nas542 |
| zyxel | nas542 firmware |
References
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-authentication-bypass-and-command-injection-vulnerabilities-in-nas-products
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-authentication-bypass-and-command-injection-vulnerabilities-in-nas-products
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