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CVE-2023-36673

HIGHCVSS 7.3/10EPSS 0.62%

Last modified

CVE-2023-36673 is a high-severity vulnerability rated 7.3/10 on the CVSS scale. An issue was discovered in Avira Phantom VPN through 2.23.1 for macOS. The VPN client insecurely configures the operating system such that all IP traffic to the VPN server's IP address is sent in plaintext outside the VPN tunnel, even if this traffic is not generated by the VPN client, while simultaneously using plaintext DNS to look up the VPN server's IP address. EPSS estimates a 0.62% chance of exploitation in the next 30 days.

Description

An issue was discovered in Avira Phantom VPN through 2.23.1 for macOS. The VPN client insecurely configures the operating system such that all IP traffic to the VPN server's IP address is sent in plaintext outside the VPN tunnel, even if this traffic is not generated by the VPN client, while simultaneously using plaintext DNS to look up the VPN server's IP address. This allows an adversary to trick the victim into sending traffic to arbitrary IP addresses in plaintext outside the VPN tunnel. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to "ServerIP attack, combined with DNS spoofing, that can leak traffic to an arbitrary IP address" rather than to only Avira Phantom VPN.

Metrics

CVSS 3.1
7.3/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

EPSS Probability
0.62%

45.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
AviraPhantom Vpn<= 2.23.1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-36673?
An issue was discovered in Avira Phantom VPN through 2.23.1 for macOS. The VPN client insecurely configures the operating system such that all IP traffic to the VPN server's IP address is sent in plaintext outside the VPN tunnel, even if this traffic is not generated by the VPN client, while simultaneously using plaintext DNS to look up the VPN server's IP address. This allows an adversary to trick the victim into sending traffic to arbitrary IP addresses in plaintext outside the VPN tunnel. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to "ServerIP attack, combined with DNS spoofing, that can leak traffic to an arbitrary IP address" rather than to only Avira Phantom VPN.
How severe is CVE-2023-36673?
CVE-2023-36673 has a CVSS score of 7.3/10 (HIGH severity). The EPSS model estimates a 0.62% probability of exploitation in the next 30 days.
How do I fix CVE-2023-36673?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-36673?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST