Oxenstored 32->31 bit integer truncation issues Integers in Ocaml are 63 or 31 bits of signed precision.

published 2022-11-01 4 y ago modified 2026-06-17 4 mo ago also EUVD-2022-45399

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

Oxenstored 32->31 bit integer truncation issues Integers in Ocaml are 63 or 31 bits of signed precision. The Ocaml Xenbus library takes a C uint32_t out of the ring and casts it directly to an Ocaml integer. In 64-bit Ocaml builds this is fine, but in 32-bit builds, it truncates off the most significant bit, and then creates unsigned/signed confusion in the remainder. This in turn can feed a negative value into logic not expecting a negative value, resulting in unexpected exceptions being thrown. The unexpected exception is not handled suitably, creating a busy-loop trying (and failing) to take the bad packet out of the xenstore ring.

Patch / fix

distros 2 links 3

debian alpine

xen Debian 14, Debian 13, Debian 12 4.16.2+90-g0d39a6d1ae-1

debian advisories DEBIAN-CVE-2022-42324

xen Alpine 3.15, Alpine 3.14 4.15.4-r0
xen Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 4.17.0-r0

alpine advisories ALPINE-CVE-2022-42324

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

xenbits.xenproject.org/xsa/advisory-420.txt advisory
xenbits.xen.org/xsa/advisory-420.html advisory
openwall.com/lists/oss-security/2022/11/01/10 advisory

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

Xen xen

Classification

Weakness

CWE-681 Incorrect Conversion between Numeric Types

References

xenbits.xenproject.org /xsa/advisory-420.txt
patch, vendor-advisory
xenbits.xen.org /xsa/advisory-420.html
patch, vendor-advisory
openwall.com /lists/oss-security/2022/11/01/10
mailing-list, patch, third-party-advisory
debian.org /security/2022/dsa-5272
vendor-advisory, third-party-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/ZLI2NPNEH7CNJO3VZGQNOI4M4EWLNKPZ/
vendor-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/YZVXG7OOOXCX6VIPEMLFDPIPUTFAYWPE/
vendor-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/YTMITQBGC23MSDHUCAPCVGLMVXIBXQTQ/
vendor-advisory
security.gentoo.org /glsa/202402-07
vendor-advisory

Sources

CVE List CVE-2022-42324
NVD CVE-2022-42324

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary