An issue was discovered in the Clario VPN client through 5.9.1.1662 for macOS.

published 2023-08-09 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-40614

cvss: 6.3; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits: 0; none known

An issue was discovered in the Clario VPN client through 5.9.1.1662 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. This allows an adversary to trick the victim into sending plaintext traffic to the VPN server's IP address and thereby deanonymize the victim. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to "ServerIP attack for only traffic to the real IP address of the VPN server" rather than to only Clario.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: total
Assessed: 2 y ago (2024-10-17)

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

tunnelcrack.mathyvanhoef.com https://tunnelcrack.mathyvanhoef.com/details.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.3	CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Classification

Weakness

CWE-319 Cleartext Transmission of Sensitive Information

References

tunnelcrack.mathyvanhoef.com /details.html
exploit, third-party-advisory
clario.co /vpn-for-mac/
product
psirt.global.sonicwall.com /vuln-detail/SNWLID-2023-0015

Sources

CVE List CVE-2023-36671
NVD CVE-2023-36671

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary