CVE-2025-31161

Confirmed PUBLISHED

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...

CrushFTP · CrushFTP
Exploited in the wild Used in malware PoC available

Recommended Action

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Confidence
Confirmed
Exploitation Status
Exploited in the wild
Observed in Sensors
No
Attempts (30d)
Unique Attacker IPs
CISA KEV
In CISA KEV
CVSS / EPSS
9.8 Critical

At a Glance

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.

ransomware nessus_scanner windows nuclei_scanner malware cisa
CVE Published
Apr 03, 2025
Exploitation Reported
Apr 07, 2025
CVSS
9.8 Critical
EPSS
Remote Low complexity No user interaction Unauthenticated

Affected Versions

Vendor Product Version Status
CrushFTP
CrushFTP

10 to < 10.8.4

Affected
CrushFTP
CrushFTP

11 to < 11.3.1

Affected

CVE References

Recommended Actions

  • Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
  • Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
  • Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.