Man-in-the-middle attack via web relay impersonation
Published Aug 13, 2021 · Updated May 30, 2025
Man-in-the-middle weakness in 2N Access Unit 2.0 firmware 2.31.0.40.5 allows man-in-the-middle attackers to impersonate its web relay. The unit trusts a host that assumes the configured relay's IP address; the published advisory does not identify the missing authentication or validation control. Exploitation requires adjacent-network access and user interaction, and the published impact is limited to information exposure and service interruption, not data modification.
Summary
What happened
Man-in-the-middle weakness in 2N Access Unit 2.0 firmware 2.31.0.40.5 allows man-in-the-middle attackers to impersonate its web relay. The unit trusts a host that assumes the configured relay's IP address; the published advisory does not identify the missing authentication or validation control. Exploitation requires adjacent-network access and user interaction, and the published impact is limited to information exposure and service interruption, not data modification.
The record
- CVE
- CVE-2021-31399
- Published
- Aug 13, 2021
- Updated
- May 30, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- T1557
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 13, 2021CVE publishedPublication date reported by the CVE source.
- May 30, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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