{"id":"CVE-2025-31161","published":"2025-04-03T20:15:25Z","modified":"2026-06-17T09:09:56Z","title":"CrushFTP Authentication Bypass Vulnerability","vendor":"CrushFTP","product":"CrushFTP","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"CrushFTP versions 10 before 10.8.4 and 11 before 11.3.1 contain an authentication bypass in the AWS4-HMAC (S3-compatible) authorization method of the server's HTTP component. An unauthenticated remote attacker with network access can exploit it, without credentials or user interaction, by winning a race condition or sending a malformed AWS4-HMAC header containing only a username and a slash, to authenticate as any known or guessable user, including the crushadmin account, unless a DMZ proxy instance is in use.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T07:10:55Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.99969,"percentile":0.99977,"date":"2026-10-31","provenance":"source"},"kev":{"dateAdded":"2025-04-07","dueDate":"2025-04-28","ransomware":true,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"https://www.crushftp.com/crush11wiki/Wiki.jsp?page=Update ; https://nvd.nist.gov/vuln/detail/CVE-2025-31161","provenance":"source"},"vulncheckKev":{"dateAdded":"2024-04-26","exploitedFirstSeen":"2025-03-31","ransomware":true,"evidence":[{"url":"https://x.com/Shadowserver/status/1906753539499520064","date":"2025-03-31"},{"url":"https://arcticwolf.com/resources/blog/cve-2025-31161/","date":"2025-04-02"},{"url":"https://outpost24.com/blog/crushftp-auth-bypass-vulnerability/","date":"2025-04-02"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-31161","date":"2025-04-03"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-04-07"},{"url":"https://www.huntress.com/blog/crushftp-cve-2025-31161-auth-bypass-and-post-exploitation","date":"2025-04-07"},{"url":"https://www.fortiguard.com/threat-signal-report/6072/crushftp-authentication-bypass","date":"2025-04-08"},{"url":"https://www.imperva.com/blog/imperva-customers-are-protected-against-cve-2025-31161-in-crushftp/","date":"2025-04-10"},{"url":"https://www.huntress.com/blog/cve-2025-30406-critical-gladinet-centrestack-triofox-vulnerability-exploited-in-the-wild","date":"2025-04-14"},{"url":"https://www.huntress.com/blog/do-tigers-really-change-their-stripes","date":"2025-05-06"}],"evidenceTotal":33,"provenance":"source"},"exploited":true,"otx":null,"cwes":[{"id":"CWE-305","name":"Authentication Bypass by Primary Weakness"}],"references":[{"url":"https://crushftp.com/crush11wiki/Wiki.jsp?page=Update#section-Update-VulnerabilityInfo","tags":["Vendor Advisory"]},{"url":"https://outpost24.com/blog/crushftp-auth-bypass-vulnerability/","tags":["Third Party Advisory"]},{"url":"https://attackerkb.com/topics/k0EgiL9Psz/cve-2025-2825/rapid7-analysis","tags":["Exploit","Third Party Advisory"]},{"url":"https://projectdiscovery.io/blog/crushftp-authentication-bypass","tags":["Exploit","Third Party Advisory"]},{"url":"https://www.darkreading.com/vulnerabilities-threats/disclosure-drama-clouds-crushftp-vulnerability-exploitation","tags":["Press/Media Coverage"]},{"url":"https://www.huntress.com/blog/crushftp-cve-2025-31161-auth-bypass-and-post-exploitation","tags":["Exploit","Third Party Advisory"]},{"url":"https://www.infosecurity-magazine.com/news/crushftp-flaw-exploited-disclosure/","tags":["Press/Media Coverage"]},{"url":"https://www.vicarius.io/vsociety/posts/cve-2025-31161-detect-crushftp-vulnerability","tags":["Exploit","Third Party Advisory"]},{"url":"https://www.vicarius.io/vsociety/posts/cve-2025-31161-mitigate-crushftp-vulnerability","tags":["Mitigation","Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-31161","tags":["US Government Resource"]}],"techniques":[{"id":"T1078","name":"Valid Accounts","tactics":["initial-access","persistence","privilege-escalation","stealth"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Authentication Bypass","mappingType":"exploitation_technique","evidence":[],"comment":"This vulnerability in CrushFTP has been exploited to give attackers control how the software handles authentication, allowing access to the administrative account. From there, attackers have the ability to read and upload files, execute arbitrary code, create backdoors in the form of new administrative accounts, and conduct a full system takeover.","confidence":"high"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Authentication Bypass","mappingType":"primary_impact","evidence":[],"comment":"This vulnerability in CrushFTP has been exploited to give attackers control how the software handles authentication, allowing access to the administrative account. From there, attackers have the ability to read and upload files, execute arbitrary code, create backdoors in the form of new administrative accounts, and conduct a full system takeover.","confidence":"high"},{"id":"T1136","name":"Create Account","tactics":["persistence"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Authentication Bypass","mappingType":"primary_impact","evidence":[],"comment":"This vulnerability in CrushFTP has been exploited to give attackers control how the software handles authentication, allowing access to the administrative account. From there, attackers have the ability to read and upload files, execute arbitrary code, create backdoors in the form of new administrative accounts, and conduct a full system takeover.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2025-9910","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-9910","exploited":true,"exploitedSince":"2025-04-07","provenance":"source"},"exploits":[{"id":52295,"url":"https://www.exploit-db.com/exploits/52295","title":"CrushFTP 11.3.1 - Authentication Bypass","type":"remote","platform":"multiple","date":"2025-05-18","verified":false,"provenance":"source"}],"exploitSources":{"exploitdb":{"count":1,"earliest":"2025-05-18"},"pocGithub":{"count":15,"skipped":5,"earliest":"2025-04-08","earliestUrl":"https://github.com/Immersive-Labs-Sec/CVE-2025-31161","repos":[{"name":"Immersive-Labs-Sec/CVE-2025-31161","url":"https://github.com/Immersive-Labs-Sec/CVE-2025-31161","stars":48,"created":"2025-04-08"},{"name":"0xgh057r3c0n/CVE-2025-31161","url":"https://github.com/0xgh057r3c0n/CVE-2025-31161","stars":5,"created":"2025-05-23"},{"name":"TX-One/CVE-2025-31161","url":"https://github.com/TX-One/CVE-2025-31161","stars":2,"created":"2025-04-21"},{"name":"f4dee-backup/CVE-2025-31161","url":"https://github.com/f4dee-backup/CVE-2025-31161","stars":2,"created":"2025-09-10"},{"name":"c4bsec/CVE-2025-31161","url":"https://github.com/c4bsec/CVE-2025-31161","stars":2,"created":"2025-10-21"}]},"nuclei":[{"id":"CVE-2025-31161","name":"CrushFTP - Authentication Bypass","severity":"critical","path":"http/cves/2025/CVE-2025-31161.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-31161.yaml"}],"first":{"date":"2025-04-08","source":"PoC-in-GitHub","url":"https://github.com/Immersive-Labs-Sec/CVE-2025-31161"},"provenance":"source"},"detections":{"cveRules":[{"title":"Suspicious CrushFTP Child Process","id":"459628e3-1b00-4e9b-9e5b-7da8961aea35","level":"medium","status":"experimental","path":"rules-emerging-threats/2025/Exploits/CVE-2025-31161/proc_creation_win_crushftp_susp_child_processes.yml","url":"https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2025/Exploits/CVE-2025-31161/proc_creation_win_crushftp_susp_child_processes.yml","techniques":["T1059.001","T1059.003","T1190"]}]},"exploitRefs":["https://attackerkb.com/topics/k0EgiL9Psz/cve-2025-2825/rapid7-analysis","https://projectdiscovery.io/blog/crushftp-authentication-bypass","https://www.huntress.com/blog/crushftp-cve-2025-31161-auth-bypass-and-post-exploitation","https://www.vicarius.io/vsociety/posts/cve-2025-31161-detect-crushftp-vulnerability"],"flow":[{"stage":"exploitation","techniques":["T1078"],"provenance":"source"},{"stage":"primary","techniques":["T1059","T1136"],"provenance":"source"}],"timeline":[{"date":"2025-03-31","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://x.com/Shadowserver/status/1906753539499520064","provenance":"source"},{"date":"2025-04-03","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-31161","provenance":"source"},{"date":"2025-04-07","kind":"kev","label":"Added to CISA KEV (known ransomware use)","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-04-07","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-9910","provenance":"source"},{"date":"2025-04-08","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub; later: Exploit-DB 2025-05-18","url":"https://github.com/Immersive-Labs-Sec/CVE-2025-31161","provenance":"source"}],"speed":{"daysToPublicExploit":5,"firstExploitFrom":"PoC-in-GitHub","daysToKev":4},"priority":{"score":76.9,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 919 days ago"},{"name":"Known ransomware use","points":10.0,"detail":"CISA KEV and VulnCheck KEV: Known"},{"name":"EPSS percentile","points":20.0,"detail":"percentile 0.9998"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"4 NVD references tagged Exploit; 1 Exploit-DB entry; 15 PoC-in-GitHub repos; 1 nuclei template"},{"name":"Mentioned in OTX pulses","points":0.0,"detail":"0 pulses"},{"name":"CVSS severity","points":6.86,"detail":"base score 9.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}