DescriptionH2O is an HTTP server. In versions 2.3.0-beta2 and prior, when the reverse proxy handler tries to processes a certain type of invalid HTTP request, it tries to build an upstream URL by reading from uninitialized pointer. This behavior can lead to crashes or leak of information to back end HTTP servers. Pull request number 3229 fixes the issue. The pull request has been merged to the `master` branch in commit f010336. Users should upgrade to commit f010336 or later.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
h2o (PTS)buster, buster (security)2.2.5+dfsg2-2+deb10u1vulnerable
bookworm, sid2.2.5+dfsg2-7vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs


[bookworm] - h2o <no-dsa> (Minor issue)
[bullseye] - h2o <no-dsa> (Minor issue)
Fixed by:
Fixed by: has done a major refactoring, but issue possibly present before

Search for package or bug name: Reporting problems