--- title: "CVE-2025-31161: Authentication Bypass by Primary Weakness | CubePath" description: "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)…" language: en source: https://cubepath.com/security/cve/CVE-2025-31161 --- # CVE-2025-31161: Authentication Bypass by Primary Weakness | CubePath ## Description 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. Official description from the CVE record, published by mitre. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2025-31161) ## Key data ### CVSS 3.1 Critical 9.8 Score published by mitre in the CVE record. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | Metric | Value | What it means | | ---------------------- | --------- | ----------------------------------------------------------------------------------- | | Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. | | Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. | | Privileges required | None | No account or privileges are needed. | | User interaction | None | No action from any user is needed. | | Scope | Unchanged | The impact stays within the vulnerable component. | | Confidentiality impact | High | Serious or total effect on the secrecy of data. | | Integrity impact | High | Serious or total effect on the trustworthiness of data. | | Availability impact | High | Serious or total effect on availability. | CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) . ### EPSS Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days. Score 0.99969 (99.96% probability) Percentile 99.97% Scores of Nov 10, 2026 Model v2026.06.15 ### CISA Known Exploited Vulnerabilities This CVE is listed in the CISA KEV catalog. Name in the catalog CrushFTP Authentication Bypass Vulnerability Added to the catalog Apr 7, 2025 Federal due date Apr 28, 2025 Ransomware campaigns Known use ### CISA assessment as of Aug 15, 2025 Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA. Exploitation Recorded by CISA as active Automatable yes Technical impact total ### Weakness (CWE) CWE catalog version 5.0. CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license. - [CWE-305](https://cwe.mitre.org/data/definitions/305.html) Authentication Bypass by Primary Weakness ## Affected products Products listed in the CVE record, as the CNA published them. - CrushFTP - affected: 10 up to before 10.8.4 - affected: 11 up to before 11.3.1 ## References Links listed in the CVE record. They lead to other sites, which CubePath does not control. - [outpost24.com/blog/crushftp-auth-bypass-vulnerability](https://outpost24.com/blog/crushftp-auth-bypass-vulnerability/) - [crushftp.com/crush11wiki/Wiki.jsp?page=Update](https://crushftp.com/crush11wiki/Wiki.jsp?page=Update#section-Update-VulnerabilityInfo) - [projectdiscovery.io/blog/crushftp-authentication-bypass](https://projectdiscovery.io/blog/crushftp-authentication-bypass) - [darkreading.com/vulnerabilities-threats/disclosure-drama-cl…](https://www.darkreading.com/vulnerabilities-threats/disclosure-drama-clouds-crushftp-vulnerability-exploitation) - [huntress.com/blog/crushftp-cve-2025-31161-auth-bypass-and-p…](https://www.huntress.com/blog/crushftp-cve-2025-31161-auth-bypass-and-post-exploitation) - [attackerkb.com/topics/k0EgiL9Psz/cve-2025-2825/rapid7-analy…](https://attackerkb.com/topics/k0EgiL9Psz/cve-2025-2825/rapid7-analysis) - [infosecurity-magazine.com/news/crushftp-flaw-exploited-disc…](https://www.infosecurity-magazine.com/news/crushftp-flaw-exploited-disclosure/) - [vicarius.io/vsociety/posts/cve-2025-31161-detect-crushftp-v…](https://www.vicarius.io/vsociety/posts/cve-2025-31161-detect-crushftp-vulnerability) - [vicarius.io/vsociety/posts/cve-2025-31161-mitigate-crushftp…](https://www.vicarius.io/vsociety/posts/cve-2025-31161-mitigate-crushftp-vulnerability) ## Timeline 1. ID reserved Mar 27, 2025 2. Record published Apr 3, 2025 3. Added to CISA KEV Apr 7, 2025 4. Record last updated Oct 21, 2025 ## Look up another CVE ## About CubePath CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection. [Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection) Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:20 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)