CVE-2025-31161
랜섬웨어 악용 CrushFTP Authentication Bypass Vulnerability
악용 여부
랜섬웨어 악용
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%
한국어 공식 권고
CISA 원문
CrushFTP contains an authentication bypass vulnerability in the HTTP authorization header that allows a remote unauthenticated attacker to authenticate to any known or guessable user account (e.g., crushadmin), potentially leading to a full compromise. — CISA KEV · shortDescription 원문
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.— CISA KEV · requiredAction 원문
취약점 설명 (NVD 원문)
CrushFTP 10 before 10.8.4 and 11 before 11.3.1 allows authentication bypass and takeover of the crushadmin account (unless a DMZ proxy instance is used), as exploited in the wild in March and April 2025, aka "Unauthenticated HTTP(S) port access." A race condition exists in the AWS4-HMAC (compatible with S3) authorization method of the HTTP component of the FTP server. The server first verifies the existence of the user by performing a call to login_user_pass() with no password requirement. This will authenticate the session through the HMAC verification process and up until the server checks for user verification once more. The vulnerability can be further stabilized, eliminating the need for successfully triggering a race condition, by sending a mangled AWS4-HMAC header. By providing only the username and a following slash (/), the server will successfully find a username, which triggers the successful anypass authentication process, but the server will fail to find the expected SignedHeaders entry, resulting in an index-out-of-bounds error that stops the code from reaching the session cleanup. Together, these issues make it trivial to authenticate as any known or guessable user (e.g., crushadmin), and can lead to a full compromise of the system by obtaining an administrative account.
CWE-305
악용 확률 변화
| 기준일 | 확률 | 백분위 |
|---|---|---|
| 2026-09-08 | 99.98% | 100.0% |
| 2026-09-07 | 99.98% | 100.0% |
| 2026-09-06 | 99.98% | 100.0% |
| 2026-09-05 | 99.98% | 100.0% |
| 2026-09-04 | 99.98% | 100.0% |