📌 이 취약점에 대해 확인된 사실
전부 발행처가 발표한 값입니다. 우리가 계산하거나 판단한 숫자는 하나도 없습니다.
악용 여부
악용 확인
심각도 (발행처 발표값)
심각9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
악용 확률 (EPSS)
100.0%
📄 원문 그대로
아래 문장은 전부 발행처가 쓴 것입니다. 번역하지 않습니다 — 보안 문서의 오역은 조치를 바꿉니다.
취약점 설명 (NVD)
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 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
CISA 원문
Multiple Zyxel network-attached storage (NAS) devices contain a pre-authentication command injection vulnerability, which may allow a remote, unauthenticated attacker to execute arbitrary code.— CISA KEV · shortDescription 원문
Apply updates per vendor instructions.— CISA KEV · requiredAction 원문
악용 확률 변화
우리가 매일 저장한 EPSS 스냅샷입니다. 원본은 전날 값만 주므로, 이 표는 수집을 시작한 이후만 보여줍니다.
| 기준일 | 확률 | 백분위 |
|---|---|---|
| 2026-11-03 | 99.99% | 100.0% |
| 2026-11-02 | 99.99% | 100.0% |
| 2026-11-01 | 99.99% | 100.0% |
| 2026-10-31 | 99.99% | 100.0% |
| 2026-10-30 | 99.99% | 100.0% |
| 2026-10-29 | 99.99% | 100.0% |
| 2026-10-28 | 99.99% | 100.0% |
| 2026-10-27 | 99.99% | 100.0% |
| 2026-10-26 | 99.99% | 100.0% |
| 2026-10-25 | 99.99% | 100.0% |
| 2026-10-24 | 99.99% | 100.0% |
| 2026-10-23 | 99.99% | 100.0% |
| 2026-10-22 | 99.99% | 100.0% |
| 2026-10-21 | 99.99% | 100.0% |
🧩 같은 약점 유형 — CWE-78
같은 분류의 다른 취약점입니다. 같은 실수가 제품을 가리지 않고 반복됩니다.