RPC traffic interception via unauthenticated dynamic port selection
Published Oct 12, 2023 · Updated Nov 4, 2025
Authentication bypass in SoftEther VPN 4.41-9782-beta and 5.01.9674 allows local users to intercept VPN Client RPC traffic. CiRpcServerThread() skips occupied ports in 9931–9936, but the manager connects to the first listening port and sends unencrypted commands without authenticating the endpoint. Exploitation requires local process execution before the client starts and can expose or alter administrator RPC traffic, including trusted-CA configuration.
Summary
What happened
Authentication bypass in SoftEther VPN 4.41-9782-beta and 5.01.9674 allows local users to intercept VPN Client RPC traffic. CiRpcServerThread() skips occupied ports in 9931–9936, but the manager connects to the first listening port and sends unencrypted commands without authenticating the endpoint. Exploitation requires local process execution before the client starts and can expose or alter administrator RPC traffic, including trusted-CA configuration.
The record
- CVE
- CVE-2023-32634
- Published
- Oct 12, 2023
- Updated
- Nov 4, 2025
- Vendor
- SoftEther VPN Project
- Product
- SoftEther VPN
- Classifications
- CWE-300, T1557
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 12, 2023CVE publishedPublication date reported by the CVE source.
- Nov 4, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.41-9782
- Affected versionversion=4.41-9782-beta
- Affected versionversion=5.01.9674
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Public exploit references
- Cisco Talos Decept TCP relay demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo