Xenstore: guests can let run xenstored out of memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Malicious guests can cause xenstored to allocate vast amounts of memory, eventually resulting in a Denial of Service (DoS) of xenstored. There are multiple ways how guests can cause large memory allocations in xenstored: - - by issuing new requests to xenstored without reading the responses, causing the responses to be buffered in memory - - by causing large number of watch events to be generated via setting up multiple xenstore watches and then e.g. deleting many xenstore nodes below the watched path - - by creating as many nodes as allowed with the maximum allowed size and path length in as many transactions as possible - - by accessing many nodes inside a transaction

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-42313
• https://xenbits.xenproject.org/xsa/advisory-326.txt
• http://xenbits.xen.org/xsa/advisory-326.html
• https://www.debian.org/security/2022/dsa-5272
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZLI2NPNEH7CNJO3VZGQNOI4M4EWLNKPZ/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YZVXG7OOOXCX6VIPEMLFDPIPUTFAYWPE/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YTMITQBGC23MSDHUCAPCVGLMVXIBXQTQ/