{"id":"CVE-2024-45397","aliases":["DEBIAN-CVE-2024-45397","EUVD-2024-41458","GHSA-jf2c-xjcp-wg4c","UBUNTU-CVE-2024-45397"],"status":"published","title":"H2O alllows bypassing address-based access control with 0-RTT","description":"h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00441,"percentile":0.38559,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-284","CWE-290"],"published":"2024-10-11T14:24:57Z","modified":"2026-11-02T12:02:48Z","affected":[{"source":"osv","ecosystem":"Debian:12","package":"h2o","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.5+dfsg2-10","2.2.5+dfsg2-11","2.2.5+dfsg2-7","2.2.5+dfsg2-8","2.2.5+dfsg2-8.1","2.2.5+dfsg2-8.1~exp1","2.2.5+dfsg2-9"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"h2o","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.3+dfsg-2","2.2.4+dfsg-1","2.2.4+dfsg-1build1","2.2.4+dfsg-1ubuntu0.1~esm2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"h2o","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.5+dfsg2-3","2.2.5+dfsg2-3build1","2.2.5+dfsg2-3ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"h2o","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.5+dfsg2-6","2.2.5+dfsg2-6.1","2.2.5+dfsg2-6.1ubuntu1","2.2.5+dfsg2-6.1ubuntu2","2.2.5+dfsg2-6.1ubuntu2+esm1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"h2o","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.5+dfsg2-7","2.2.5+dfsg2-8","2.2.5+dfsg2-8.1ubuntu1","2.2.5+dfsg2-8.1ubuntu2","2.2.5+dfsg2-8.1ubuntu3"]}],"products":[{"vendor":"dena","product":"h2o"},{"vendor":"h2o","product":"h2o"}],"references":[{"url":"https://github.com/h2o/h2o/security/advisories/GHSA-jf2c-xjcp-wg4c","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","report"]},{"url":"https://github.com/h2o/h2o/commit/15ed15a2efb83a77bb4baaa5a119e639c2f6898a","tags":["x_refsource_MISC","Patch","fix","report"]},{"url":"https://h2o.examp1e.net/configure/http3_directives.html","tags":["x_refsource_MISC","Product","web","report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/45xxx/CVE-2024-45397.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-45397","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2024-45397","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2024-45397","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2024-45397","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2024-45397","title":"H2O alllows bypassing address-based access control with 0-RTT","description":"h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.","status":"published","published":"2024-10-11T14:24:57.687Z","modified":"2024-10-11T14:42:24.963Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T14:34:08.16279Z"}],"euvd":[{"id":"EUVD-2024-41458","description":"h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.","status":"published","published":"2024-10-11T14:24:57Z","modified":"2024-10-11T14:42:24Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T00:27:39.67018Z"}],"nvd":[{"id":"CVE-2024-45397","description":"h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.","status":"published","published":"2024-10-11T15:15:04.69Z","modified":"2026-06-17T07:54:08.137Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-284","CWE-290"],"updated_at":"2026-11-02T14:10:31.879321Z"}],"osv":[{"id":"CVE-2024-45397","title":"H2O alllows bypassing address-based access control with 0-RTT","description":"h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.","status":"published","published":"2024-10-11T14:24:57.687Z","modified":"2026-10-28T02:30:31.902538447Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-284"],"updated_at":"2026-11-02T15:44:42.790566Z"},{"id":"DEBIAN-CVE-2024-45397","description":"h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.","status":"published","published":"2024-10-11T15:15:04.69Z","modified":"2026-11-02T12:02:48.758259838Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:43.473331Z"},{"id":"UBUNTU-CVE-2024-45397","description":"h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.","status":"published","published":"2024-10-11T15:15:00Z","modified":"2026-04-22T15:06:35.335139Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T16:55:02.636559Z"}]}}