Traffic interception via accepted hostname-validation errors
Published Feb 27, 2020 · Updated Aug 4, 2024
Improper certificate validation in openfortivpn 1.11.0 allows man-in-the-middle attackers to intercept VPN client traffic. In tunnel.c, ssl_verify_cert treats every nonzero X509_check_host result as a match, so malformed-name errors mark a hostile certificate valid. Exploitation requires a network position and a CA-signed certificate containing a null byte in its SAN or CommonName, enabling traffic interception.
Summary
What happened
Improper certificate validation in openfortivpn 1.11.0 allows man-in-the-middle attackers to intercept VPN client traffic. In tunnel.c, ssl_verify_cert treats every nonzero X509_check_host result as a match, so malformed-name errors mark a hostile certificate valid. Exploitation requires a network position and a CA-signed certificate containing a null byte in its SAN or CommonName, enabling traffic interception.
The record
- CVE
- CVE-2020-7041
- Published
- Feb 27, 2020
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-295, T1557
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 27, 2020CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- GitHub Security Lab malformed-certificate proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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