CVE-2020-7043
📋 TL;DR
This vulnerability allows attackers to perform man-in-the-middle attacks by exploiting improper certificate validation in openfortivpn. The software fails to properly compare hostnames when validating SSL certificates, allowing attackers to present malicious certificates that appear valid. This affects openfortivpn 1.11.0 users with OpenSSL versions before 1.0.2.
💻 Affected Systems
- openfortivpn
📦 What is this software?
Backports Sle by Opensuse
Fedora by Fedoraproject
Fedora by Fedoraproject
Fedora by Fedoraproject
Leap by Opensuse
Openfortivpn by Openfortivpn Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers can intercept and decrypt all VPN traffic, potentially gaining access to sensitive internal network resources and credentials.
Likely Case
Man-in-the-middle attacks allowing traffic interception and potential credential theft from VPN connections.
If Mitigated
Limited impact with proper network segmentation and certificate pinning, though VPN security would still be compromised.
🎯 Exploit Status
Exploitation requires man-in-the-middle position but is straightforward once that position is achieved.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in openfortivpn commit 6328a070ddaab16faaf008cb9a8a62439c30f2a8 and later
Vendor Advisory: https://github.com/adrienverge/openfortivpn/commit/6328a070ddaab16faaf008cb9a8a62439c30f2a8
Restart Required: Yes
Instructions:
1. Update openfortivpn to version after commit 6328a070ddaab16faaf008cb9a8a62439c30f2a8
2. Ensure OpenSSL is updated to 1.0.2 or later
3. Restart openfortivpn service
🔧 Temporary Workarounds
Update OpenSSL
linuxUpdate OpenSSL to version 1.0.2 or later to mitigate the vulnerability
sudo apt-get update && sudo apt-get upgrade openssl
sudo yum update openssl
🧯 If You Can't Patch
- Implement certificate pinning for VPN connections
- Use alternative VPN solutions until patching is possible
🔍 How to Verify
Check if Vulnerable:
Check openfortivpn version with 'openfortivpn --version' and verify it's 1.11.0, then check OpenSSL version with 'openssl version'Check Version:
openfortivpn --version && openssl versionVerify Fix Applied:
Verify openfortivpn version is after commit 6328a070ddaab16faaf008cb9a8a62439c30f2a8 and OpenSSL is 1.0.2 or later📡 Detection & Monitoring
Log Indicators:
- Unusual certificate validation failures
- Multiple connection attempts with different certificates
Network Indicators:
- Unexpected certificate changes during VPN handshake
- SSL/TLS handshake anomalies
SIEM Query:
source="openfortivpn" AND (certificate_validation="failed" OR certificate_mismatch="true")🔗 References
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00009.html
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00011.html
- https://github.com/adrienverge/openfortivpn/commit/6328a070ddaab16faaf008cb9a8a62439c30f2a8
- https://github.com/adrienverge/openfortivpn/commit/cd9368c6a1b4ef91d77bb3fdbe2e5bc34aa6f4c4
- https://github.com/adrienverge/openfortivpn/issues/536
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CKNKSGBVYGRRVRLFEFBEKUEJYJR5LWOF/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FF6HYIBREQGATRM5COF57MRQWKOKCWZ3/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SRVVNXCNTNMPCIAZIVR4FAGYCSU53FNA/
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00009.html
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00011.html
- https://github.com/adrienverge/openfortivpn/commit/6328a070ddaab16faaf008cb9a8a62439c30f2a8
- https://github.com/adrienverge/openfortivpn/commit/cd9368c6a1b4ef91d77bb3fdbe2e5bc34aa6f4c4
- https://github.com/adrienverge/openfortivpn/issues/536
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CKNKSGBVYGRRVRLFEFBEKUEJYJR5LWOF/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FF6HYIBREQGATRM5COF57MRQWKOKCWZ3/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SRVVNXCNTNMPCIAZIVR4FAGYCSU53FNA/
