CVE-2025-47812: Wing FTP Server Improper Neutralization of Null Byte or NUL Character Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Wing FTP Server Wing FTP Server. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-07-14, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-08-04; treat that as the outer limit, not the target.
• EPSS 93.9%, percentile 99.8: FIRST’s model estimates a 93.9% chance of exploitation activity in the next 30 days, higher than 99.8% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

What it is

In Wing FTP Server before 7.4.4. the user and admin web interfaces mishandle '\0' bytes, ultimately allowing injection of arbitrary Lua code into user session files. This can be used to execute arbitrary system commands with the privileges of the FTP service (root or SYSTEM by default). This is thus a remote code execution vulnerability that guarantees a total server compromise. This is also exploitable via anonymous FTP accounts.

CISA’s summary

Wing FTP Server contains an improper neutralization of null byte or NUL character vulnerability that can allow injection of arbitrary Lua code into user session files. This can be used to execute arbitrary system commands with the privileges of the FTP service (root or SYSTEM by default).

Weakness type: CWE-158.

Product: Wing FTP Server Wing FTP Server · Assigned by: mitre · Published: 2025-07-10

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2025-07-14; federal due date 2025-08-04. Known ransomware use: Unknown.
• CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
• CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 93.88% probability of exploitation activity in the next 30 days; percentile 99.8.

Timeline

• 2025-07-10 — CVE record published by mitre
• 2025-07-14 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2025-08-04 — CISA remediation deadline for US federal agencies
• 2026-02-26 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. Listed in CISA KEV notes (wftpserver.com) wftpserver.com

Vulnerability records

1. CVE.org record CVE-2025-47812 cve.org
2. NVD entry CVE-2025-47812 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

1. wftpserver.com wftpserver.com
2. rcesecurity.com rcesecurity.com
3. vicarius.io vicarius.io
4. vicarius.io vicarius.io
5. huntress.com huntress.com

All exploited Wing FTP Server vulnerabilities · Today’s Security Digest