CVE-2025-31161

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

• https://crushftp.com/crush11wiki/Wiki.jsp?page=Update#section-Update-VulnerabilityInfoVendor Advisory
• https://outpost24.com/blog/crushftp-auth-bypass-vulnerability/Third Party Advisory
• https://attackerkb.com/topics/k0EgiL9Psz/cve-2025-2825/rapid7-analysisExploit, Third Party Advisory
• https://projectdiscovery.io/blog/crushftp-authentication-bypassExploit, Third Party Advisory
• https://www.darkreading.com/vulnerabilities-threats/disclosure-drama-clouds-crushftp-vulnerability-exploitationPress/Media Coverage
• https://www.huntress.com/blog/crushftp-cve-2025-31161-auth-bypass-and-post-exploitationExploit, Third Party Advisory
• https://www.infosecurity-magazine.com/news/crushftp-flaw-exploited-disclosure/Press/Media Coverage
• https://www.vicarius.io/vsociety/posts/cve-2025-31161-detect-crushftp-vulnerabilityExploit, Third Party Advisory
• https://www.vicarius.io/vsociety/posts/cve-2025-31161-mitigate-crushftp-vulnerabilityMitigation, Third Party Advisory
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-31161US Government Resource

Published

Apr 3, 2025

Last Modified

Jun 17, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2025-31145Rejected reason: This CVE ID has been rejected or withdrawn …
• CVE-2025-31146Time-of-check time-of-use race condition for some Intel Ethe…6.1
• CVE-2025-31147Unauthenticated attackers can query information about total …6.9
• CVE-2025-3115Injection Vulnerabilities: Attackers can inject malicious co…9.8
• CVE-2025-3116CWE-20: Improper Input Validation vulnerability exists that …7.1
• CVE-2025-31160atop through 2.11.0 allows local users to cause a denial of …2.9
• CVE-2025-31162Floating point exception in fig2dev in version 3.2.9a allows…6.6
• CVE-2025-31163Segmentation fault in fig2dev in version 3.2.9a allows an at…6.6
• CVE-2025-31164heap-buffer overflow in fig2dev in version 3.2.9a allows an …6.6
• CVE-2025-31165Cross-Site Scripting (XSS) vulnerability in the Logbug modul…6.9
• CVE-2025-3117CWE-79: Improper Neutralization of Input During Web Page Gen…5.4
• CVE-2025-31170Access control vulnerability in the security verification mo…9.1