Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2025-34047

Leadsec VPN Path Traversal Arbitrary File Read

Beijing NetGuard Nebula Information Technology / Leadsec SSL VPN · 0

Watch CVE-2025-34047 Browse KEV feed
Severity
CVSS 8.7 · High
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
0.5%
First observed
21 Jun 2026
Last observed
21 Oct 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2025-34047 is an unauthenticated Leadsec VPN Path Traversal Arbitrary File Read affecting Beijing NetGuard Nebula Information Technology Leadsec SSL VPN. A path traversal vulnerability exists in the Leadsec SSL...

Is it exploited?

Yes. Previdian sensors observed exploitation attempts with confirmed confidence. Also confirmed by third-party sources.

Who is affected?

Beijing NetGuard Nebula Information Technology / Leadsec SSL VPN 0.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

Leadsec VPN Path Traversal Arbitrary File Read

A path traversal vulnerability exists in the Leadsec SSL VPN (formerly Lenovo NetGuard), allowing unauthenticated attackers to read arbitrary files on the underlying system via the ostype parameter in the /vpn/user/download/client endpoint.

This flaw arises from insufficient input sanitation, enabling traversal sequences to escape the intended directory and access sensitive files. Exploitation evidence was observed by the Shadowserver Foundation on 2025-02-05 UTC.

Beijing NetGuard Nebula Information Technology Co., Ltd. Affected
Leadsec SSL VPN
0
View vendor advisory (opens in new tab)
Published
26 Jun 2025
Exploitation Reported
04 Feb 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

The Shadowserver

Recorded 04 Feb 2026

A trusted third party reported exploitation.

Active exploitation observed

Previdian sensor

First observed 21 Jun 2026

Previdian first observed exploitation attempts targeting this vulnerability in our honeypot sensors.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
The Shadowserver First 2026-02-04 00:00 UTC
Previdian Sensors 2026-09-30 11:25 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Previdian sensors recorded exploitation attempts targeting this vulnerability. The cards and chart show volume, unique attackers, and daily activity.

19

Attempts observed

15

Unique attacker IPs

14

Attacker countries

AF · AT · CH · CN · FI · FR · HU · IN · JP · LT · NL · SC · US · YE

13

Sensors observed

CVE-2025-34047 exploitation attempts over the last 91 days

Daily events observed by Previdian sensors

Updated 22 Oct 2026

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3
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24 Jul 12 Aug 31 Aug 19 Sep 22 Oct

First observed 21 Jun 2026 · Last observed 21 Oct 2026

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
1
7
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

Previdian virtual patch guidance is available for this CVE.

AWS WAF Cloudflare ModSecurity

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

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Virtual Patch Detail

Compensating WAF rules for this CVE.

Available

Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to Previdian Enterprise users.

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Risk and context

Severity, weaknesses, and research context

CVSS v4.0

8.7 High

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS

0.5%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Input Validation CWE-20 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE-22

Timeline

From disclosure to observed exploitation

  1. 13:38 UTC

    Virtual patch available

    Compensating WAF rule available to block exploitation

  2. 14:42 UTC

    Indicators of compromise added (34)

    Indicators of compromise recorded

  3. 14:42 UTC

    Observed by Previdian sensors

    Evidence-backed exploitation signal

  4. 00:00 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  5. 16:10 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 19:15 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2025-34047

Sample API response 
{
  "cve_id": "CVE-2025-34047",
  "confidence": "Confirmed",
  "cvss_score": 8.7,
  "cvss_estimated": false,
  "epss_score": 0.00548,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 19, "sensors": 13 }
}