Vulnerability · Published Aug 9, 2023 · Assigned by mitre
CVE-2023-36671
Medium 6.3
In plain English
A medium-severity security flaw in the openconnect package (Ubuntu). Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | openconnect | no fix listed | UBUNTU-CVE-2023-36671 |
| Ubuntu:24.04:LTS | openconnect | no fix listed | UBUNTU-CVE-2023-36671 |
| Ubuntu:22.04:LTS | softether-vpn | no fix listed | UBUNTU-CVE-2023-36671 |
| Ubuntu:24.04:LTS | softether-vpn | no fix listed | UBUNTU-CVE-2023-36671 |