Cyber Resilience

CVE-2023-32634

Softether Vpn 4.41-9782 … 5.01.9674

Public PoC
Published
12 October 2023
Modified
04 November 2025
Patch / advisory
View advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0043 35th percentile
Risk Priority 57 floored blend · peak EPSS

Summary

CVE-2023-32634 is a high-severity Channel Accessible by Non-Endpoint (CWE-300) vulnerability in Softether Vpn. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 35th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

An authentication bypass vulnerability exists in the CiRpcServerThread() functionality of SoftEther VPN 5.01.9674 and 4.41-9782-beta. An attacker can perform a local man-in-the-middle attack to trigger this vulnerability.

CWE(s)
CWE-300NVD-CWE-Other

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
attack.mitre.org →
T1557.001 Name Resolution Poisoning and SMB Relay Credential Access
By responding to LLMNR/NBT-NS/mDNS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system.
attack.mitre.org →
T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
attack.mitre.org →
T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
attack.mitre.org →
T1557.004 Evil Twin Credential Access
Adversaries may host seemingly genuine Wi-Fi access points to deceive users into connecting to malicious networks as a way of supporting follow-on behaviors such as [Network Sniffing](https://attack.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-32275Same product: Softether Vpn
CVE-2025-25567Same product: Softether Vpn
CVE-2023-22308Same product: Softether Vpn
CVE-2023-22325Same product: Softether Vpn
CVE-2025-25565Same product: Softether Vpn
CVE-2023-27395Same product: Softether Vpn
CVE-2025-25568Same product: Softether Vpn
CVE-2023-25774Same product: Softether Vpn
CVE-2023-27516Same product: Softether Vpn
CVE-2023-23581Same product: Softether Vpn

Affected Assets

softether
vpn
4.41-9782, 5.01.9674

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V12.3.5

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.

IA-3 Device Identification and Authentication
addresses: CWE-300

Ensures only authenticated endpoints can access the communication channel, blocking unauthorized non-endpoint access.

PE-4 Access Control for Transmission
addresses: CWE-300

Physically restricts transmission channels so they cannot be accessed or tapped by non-endpoint actors within facilities.

RA-6 Technical Surveillance Countermeasures Survey
addresses: CWE-300

Periodic TSCM surveys identify unauthorized access points or taps that make communication channels reachable by non-endpoint adversaries.

SC-11 Trusted Path
addresses: CWE-300

Explicitly isolates the communications path so it cannot be accessed or intercepted by non-endpoint entities during security functions.

SC-19 Voice Over Internet Protocol
addresses: CWE-300

Restrictions and channel controls reduce the chance that VoIP media or signaling streams remain accessible to non-participants.

SC-23 Session Authenticity
addresses: CWE-300

Directly prevents non-endpoint access or interception of the session communication path.

SC-37 Out-of-band Channels
addresses: CWE-300

An out-of-band channel is inaccessible to non-endpoints that can observe or interfere with the primary communication channel.

SC-40 Wireless Link Protection
addresses: CWE-300

The control restricts an inherently broadcast wireless channel to only intended endpoints, mitigating accessibility by non-endpoints.

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.

PR.AA-03 mostly match
prevents

Enforces authentication of endpoints, mitigating non-endpoint access but not channel integrity itself.

PR.DS-02 mostly match
prevents

Directly protects integrity of data-in-transit, addressing channel integrity but not endpoint identity verification.

PR.AA-04 partial match
prevents

Supports verification of identity assertions exchanged over the channel.

PR.IR-01 partial match
prevents

Reduces unauthorized network access that could exploit an unprotected channel.

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.8.24 Use of cryptography mostly match
prevents

Cryptography provides channel integrity and can support endpoint authentication.

A.8.5 Secure authentication mostly match
prevents

Secure authentication mechanisms verify actor identity at both ends of the channel.

A.5.14 Information transfer partial match
prevents

Information transfer policies address secure exchange but are high-level and not technical.

A.8.20 Networks security partial match
mitigates

Network security controls directly address channel integrity and endpoint authentication.

A.8.21 Security of network services partial match
mitigates

Security of network services includes measures to verify endpoints and protect channel integrity.

A.8.22 Segregation of networks partial match
mitigates

Network segregation reduces exposure but does not verify endpoint identity or channel integrity.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (4 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-300
  • V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-300
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-300
Oracle Linux 9 (1 rule)
  • V-271462 OL 9 must not have a File Transfer Protocol (FTP) server package installed. prevents CWE-300

References