CVE-2022-42324

CVE-2022-42324 is a medium-severity vulnerability in Xen with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-681.

Key facts

Description

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.

Frequently asked questions

What is CVE-2022-42324?
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.
How severe is CVE-2022-42324?
CVE-2022-42324 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2022-42324 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-42324?
CVE-2022-42324 primarily affects Xen. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2022-42324?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2022-42324 published?
CVE-2022-42324 was published on 2022-11-01 and last updated on 2026-06-17.

References

Affected products (5)

More vulnerabilities in Xen

All CVEs affecting Xen →

Other CWE-681 vulnerabilities

Browse all CWE-681 vulnerabilities →