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Full vulnerability report · 2025
CVE-2025-47812High confidence

Wing FTP Server Improper Neutralization of Null Byte or NUL Character Vulnerability

Wing FTP Server · Wing FTP Server

10.0CriticalCVSS 3.1
Recommended action
Mitigate now

CISA confirms exploitation in the wild and lists 2025-08-04 as the remediation due date.

Mitigation available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • CISA confirms exploitation in the wild.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 93.23% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Wing FTP Server Wing FTP Server and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-21009

CISA KEV mirrored by ENISA

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.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 14 Jul 2025. Evidence sources: cisa_kev.
ENISA score
10.0 · CVSS 3.1
Advisory evidence
1 linked advisory record
Explicit mitigation evidence

Only statements that explicitly mention a fix, patch, update, workaround or mitigation are shown here.

  • csaf_ncscnl · NCSC-2025-0230Kwetsbaarheid verholpen in Wing FTP Server
Recommended actionMitigate now

CISA confirms exploitation in the wild and lists 2025-08-04 as the remediation due date.

Mitigation available
01

What, why and how

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).

What

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).

Why

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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).

Why

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2025-07-14.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Improper Neutralization of Null Byte or NUL Character → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-158 ↗

CWE-158: Improper Neutralization of Null Byte or NUL Character. The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-158CISA KEVPublic exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2025-21009Known-exploited evidence recorded

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.

Official EUVD record ↗
Canadian Centre for Cyber Security · English · AV25-391Wing FTP security advisory (AV25-391) - Update 2

On May 14, 2025, Wing FTP a published an update to address a critical vulnerability in the following product: Open-source reporting has indicated that proof-of-concept exploit code is available for CVE-2025-47812.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20250716Security Bulletin 16 Jul 2025 [922 KB]

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 16 Jul 2025 [922 KB], published on 16 July 2025. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-008978WING FTP software の Wing FTP Server における NULL バイトまたは NULL キャラクタの無害化に関する脆弱性

WING FTP software の Wing FTP Server には、NULL バイトまたは NULL キャラクタの無害化に関する脆弱性が存在します。

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-009382WING FTP software の Wing FTP Server におけるシステム構成または設定の外部制御に関する脆弱性

WING FTP software の Wing FTP Server には、システム構成または設定の外部制御に関する脆弱性が存在します。

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-009390WING FTP software の Wing FTP Server における危険なアクションで定義された権限に関する脆弱性

WING FTP software の Wing FTP Server には、危険なアクションで定義された権限に関する脆弱性が存在します。

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2025-009219WING FTP software の Wing FTP Server におけるエラーメッセージによる情報漏えいに関する脆弱性

WING FTP software の Wing FTP Server には、エラーメッセージによる情報漏えいに関する脆弱性が存在します。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6529美 CISA 발표 주요 Exploit 정보공유(Update. 2025-07-14)

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).

Official advisory ↗
NCSC-NL · Dutch · NCSC-2025-0230Kwetsbaarheid verholpen in Wing FTP Server

De kwetsbaarheid bevindt zich in de wijze waarop Wing FTP Server null bytes verwerkt in de user parameter. Dit stelt een kwaadwillende op afstand in staat om willekeurige Lua-code te injecteren in sessie bestanden, wat kan leiden tot de uitvoering van willekeurige code met rechten van de applicatie. Het is mogelijk dat de applicatie draait met verhoogde rechten, waardoor code executie mogelijk is onder ROOT/SYSTEM-rechten. Voor succesvol misbruik moet er geldige authenticatie plaatsvinden, of anonymous FTP moet ingeschakeld zijn. Standaard is anonymous FTP uitgeschakeld. Onderzoekers hebben een exploit gepubliceerd waarmee de kwetsbaarheid kan worden misbruikt. Daarnaast melden diverse organisaties actief misbruik waar te nemen.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Mitigation available
Affected
Wing FTP Server: < 7.4.4
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Apply the mitigation in the linked authoritative guidance while planning the vendor's permanent fix.
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 10 Jul 2025 · Last source change 26 Feb 2026, 17:50 UTC · CWE-158 · Improper Neutralization of Null Byte or NUL Character

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-21009
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    < 7.4.4 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Wing FTP Server: < 7.4.4 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Mitigation reference recorded
ENISA EUVD · EUVD-2025-21009↗CISA KEV record↗Mitigation reference↗CVE authority or vendor reference↗Public exploit reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-47812 · cve.blacktree.nl