{"id":"PYSEC-2023-321","details":"The WireGuard client 0.5.3 on Windows insecurely configures the operating system and firewall such that traffic to a local network that uses non-RFC1918 IP addresses is blocked. This allows an adversary to trick the victim into blocking IP traffic to selected IP addresses and services even while the VPN is enabled. NOTE: the tunnelcrack.mathyvanhoef.com website uses this CVE ID to refer more generally to \"LocalNet attack resulting in the blocking of traffic\" rather than to only WireGuard.","aliases":["CVE-2023-35838"],"modified":"2026-05-21T15:00:33.766466434Z","published":"2023-08-09T23:15:10.007Z","references":[{"type":"WEB","url":"https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2023-0015"},{"type":"WEB","url":"https://wireguard.com"},{"type":"EVIDENCE","url":"https://tunnelcrack.mathyvanhoef.com/details.html"}],"affected":[{"package":{"name":"wireguard","ecosystem":"PyPI","purl":"pkg:pypi/wireguard"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.5.3"}]}],"versions":["0.1.0","0.1.1","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.4.0"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/wireguard/PYSEC-2023-321.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}