Security Resilience

CVE-2023-27395

Memory Safety in Softether Vpn 4.41-9782 … 5.02

Public PoCMemory Safety
Published
12 October 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 9.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.015 74th percentile
Risk Priority 66 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-27395 is a critical-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Softether Vpn. Its CVSS base score is 9.0 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 26% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

A heap-based buffer overflow vulnerability exists in the vpnserver WpcParsePacket() functionality of SoftEther VPN 4.41-9782-beta, 5.01.9674 and 5.02. A specially crafted network packet can lead to arbitrary code execution. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.

CWE(s)
CWE-122CWE-787

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
attack.mitre.org →
T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
attack.mitre.org →
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-46520Shared CWE-122, CWE-787
CVE-2024-39518Shared CWE-122, CWE-787
CVE-2025-27177Shared CWE-122, CWE-787
CVE-2023-4692Shared CWE-122, CWE-787
CVE-2026-40691Shared CWE-122, CWE-787
CVE-2026-12844Shared CWE-122, CWE-787
CVE-2024-4559Shared CWE-122, CWE-787
CVE-2023-1906Shared CWE-122, CWE-787
CVE-2025-1656Shared CWE-122, CWE-787
CVE-2023-27390Shared CWE-122, CWE-787

Affected Assets

softether
vpn
4.41-9782, 5.01.9674, 5.02

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.RA-01 partial match
blocks

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
blocks

Timely patching removes known heap-overflow instances after they exist.

PR.PS-06 partial match
blocks

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.7.2 Physical entry partial match
removes

References