DDNS client hang via receive-size integer overflow
Published Oct 12, 2023 · Updated Aug 2, 2024
Integer overflow in SoftEther VPN 4.41-9782-beta, 5.01.9674, and 5.02 allows man-in-the-middle attackers to stop the DDNS client. AdjustBufSize doubles a 32-bit reserved-size value while processing an attacker-inflated DDNS response length, causing the value to wrap and the allocation loop to run indefinitely. Exploitation requires control of NAT-T and DDNS traffic; the resulting hang prevents address-change registration until the VPN Server restarts.
Summary
What happened
Integer overflow in SoftEther VPN 4.41-9782-beta, 5.01.9674, and 5.02 allows man-in-the-middle attackers to stop the DDNS client. AdjustBufSize doubles a 32-bit reserved-size value while processing an attacker-inflated DDNS response length, causing the value to wrap and the allocation loop to run indefinitely. Exploitation requires control of NAT-T and DDNS traffic; the resulting hang prevents address-change registration until the VPN Server restarts.
The record
- CVE
- CVE-2023-22325
- Published
- Oct 12, 2023
- Updated
- Aug 2, 2024
- Vendor
- SoftEther VPN Project
- Product
- SoftEther VPN
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 12, 2023CVE publishedPublication date reported by the CVE source.
- Aug 2, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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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
- Affected versionversion=5.02
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.
Weakness, pattern, technique
Public exploit references
- Cisco Talos DDNS receive-size proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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