CVE-2023-32634 — An authentication bypass vulnerability exists in the CiRpcServerThread() functio

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.

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
SoftEther VPN	SoftEther VPN	4.41-9782-beta, 5.01.9674

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-10-12T15:27:51.751Z
• Last modified: 2025-11-04T19:16:23.506Z

09References

• talosintelligence.com — https://talosintelligence.com/vulnerability_reports/TALOS-2023-1755
• www.softether.org — https://www.softether.org/9-about/News/904-SEVPN202301