CVE-2025-34047Known exploitationPublic exploitNetwork attack vector

Arbitrary file read via ostype path traversal

Published Jun 26, 2025 · Updated Dec 23, 2025

Path traversal in Leadsec SSL VPN allows remote attackers to read arbitrary system files through its unauthenticated download endpoint. The /vpn/user/download/client handler uses the ostype parameter as a filesystem path without removing traversal sequences, letting the path escape its intended directory. No authentication or user interaction is required; successful requests disclose file contents but do not provide file modification or service interruption.

CVSS severity8.7
High
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Leadsec SSL VPN allows remote attackers to read arbitrary system files through its unauthenticated download endpoint. The /vpn/user/download/client handler uses the ostype parameter as a filesystem path without removing traversal sequences, letting the path escape its intended directory. No authentication or user interaction is required; successful requests disclose file contents but do not provide file modification or service interruption.

The record

CVE
CVE-2025-34047
Published
Jun 26, 2025
Updated
Dec 23, 2025
Vendor
Beijing NetGuard Nebula Information Technology Co., Ltd.
Product
Leadsec SSL VPN
Classifications
CWE-22, T1005, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 5, 2025Exploitation reportedShadowserver honeypot exploitation evidence
  2. Jun 26, 2025CVE publishedPublication date reported by the CVE source.
  3. Dec 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Beijing NetGuard Nebula Information Technology Co., Ltd. · Leadsec SSL VPNversion=0

Published CVSS scores

8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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