CVE-2025-34299: Monsta FTP <= 2.11 Unauthenticated Arbitrary File Upload

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 72.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-11-07 · updated 2026-10-18
Weakness: CWE-434

Description

Monsta FTP versions 2.11 and earlier contain a vulnerability that allows unauthenticated arbitrary file uploads. This flaw enables attackers to execute arbitrary code by uploading a specially crafted file from a malicious (S)FTP server.

Affected products

Monsta Limited of New Zealand Monsta FTP: through 2.11

References

https://labs.watchtowr.com/whats-that-coming-over-the-hill-monsta-ftp-remote-code-execution-cve-2025-34299/
https://www.monstaftp.com/notes/
https://www.vulncheck.com/advisories/monsta-ftp-unauthenticated-arbitrary-file-upload

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