CVE-2025-25565Public exploit

Local vpncmd crash via unchecked numeric-field length

Published Mar 12, 2025 · Updated Jul 19, 2025

Buffer overflow in SoftEther VPN 5.02.5187 vpncmd allows local users to crash the utility through certificate commands. The PtMakeCert and PtMakeCert2048 paths process an overlong certificate-validity value without a length check in UniToStrForSingleChars, overrunning an array. Triggering requires a local administrator to deliberately enter the oversized value; the supplier disputes any security impact beyond termination of that administrator's vpncmd process.

CVSS severity9.8
Critical
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in SoftEther VPN 5.02.5187 vpncmd allows local users to crash the utility through certificate commands. The PtMakeCert and PtMakeCert2048 paths process an overlong certificate-validity value without a length check in UniToStrForSingleChars, overrunning an array. Triggering requires a local administrator to deliberately enter the oversized value; the supplier disputes any security impact beyond termination of that administrator's vpncmd process.

The record

CVE
CVE-2025-25565
Published
Mar 12, 2025
Updated
Jul 19, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 12, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

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No observations available

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

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Public exploit references

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

Technologies

Your stack

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Your stack

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