{"id":"CVE-2021-32836","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-32836","generatedAt":"2026-10-27T21:20:07.789Z","title":"In ZStack before versions 3.10.12 and 4.1.6 there is a pre-auth unsafe deserialization vulnerability in the REST API.","description":"ZStack is open source IaaS(infrastructure as a service) software. In ZStack before versions 3.10.12 and 4.1.6 there is a pre-auth unsafe deserialization vulnerability in the REST API. An attacker in control of the request body will be able to provide both the class name and the data to be deserialized and therefore will be able to instantiate an arbitrary type and assign arbitrary values to its fields. This issue may lead to a Denial Of Service. If a suitable gadget is available, then an attacker may also be able to exploit this vulnerability to gain pre-auth remote code execution. For additional details see the referenced GHSL-2021-087.","published":"2021-09-09T02:15:15.000Z","lastModified":"2026-06-17T03:53:44.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-94","CWE-502"],"affected":["zstack/zstack"],"epss":{"score":0.02036,"percentile":0.80954,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.04%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/zstackio/zstack/security/advisories/GHSA-jfvq-548h-342x","tags":["Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://securitylab.github.com/advisories/GHSL-2021-087-zstack/","tags":["Exploit","Third Party Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/zstackio/zstack/security/advisories/GHSA-jfvq-548h-342x","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://securitylab.github.com/advisories/GHSL-2021-087-zstack/","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-32836","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}