CVE-2024-45397: h2o Access Control Flaw — Fix

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.

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CVSS v3.1 Score

5.9

MEDIUM

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

Weakness Type (CWE)

CWE-284 CWE-284

CWE-290 CWE-290

Affected Products

Vendor	Product	Versions
dena	h2o	< 2024-10-10

References

Advisories & Patches

https://github.com/h2o/h2o/commit/15ed15a2efb83a77bb4baaa5a119e639c2f6898a https://github.com/h2o/h2o/security/advisories/GHSA-jf2c-xjcp-wg4c

Other References

https://h2o.examp1e.net/configure/http3_directives.html

Frequently Asked Questions

What is CVE-2024-45397? +

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. It has a CVSS v3.1 base score of 5.9 (MEDIUM).

How severe is CVE-2024-45397? +

CVE-2024-45397 has a CVSS v3.1 score of 5.9 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-45397? +

CVE-2024-45397 affects products from dena, specifically: h2o. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-45397? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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