Vpn
CVE-2025-25567
CRITICAL
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
3DescriptionCVE.org
SoftEther VPN 5.02.5187 is vulnerable to Buffer Overflow in Internat.c via the UniToStrForSingleChars function. NOTE: the Supplier disputes this because the behavior only enables a local user to attack himself through the UI,
AnalysisAI
SoftEther VPN 5.02.5187 is vulnerable to Buffer Overflow in Internat.c via the UniToStrForSingleChars function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Technical ContextAI
This vulnerability is classified as Buffer Copy without Size Check (CWE-120), which allows attackers to overflow a buffer to corrupt adjacent memory. SoftEther VPN 5.02.5187 is vulnerable to Buffer Overflow in Internat.c via the UniToStrForSingleChars function. NOTE: the Supplier disputes this because the behavior only enables a local user to attack himself through the UI, Affected products include: Softether Vpn.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Always validate buffer sizes before copy operations. Use bounded functions (strncpy, snprintf). Enable compiler protections.
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External POC / Exploit Code
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