CVE-2021-32836
In ZStack before versions 3.10.12 and 4.1.6 there is a pre-auth unsafe deserialization vulnerability in the REST API.
Does this matter?
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.
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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.04% probability · 81th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-94, CWE-502
- Affected
- zstack/zstack
- Source
- security-advisories@github.com
EPSS 2.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/zstackio/zstack/security/advisories/GHSA-jfvq-548h-342xThird Party Advisory
- https://securitylab.github.com/advisories/GHSL-2021-087-zstack/Exploit, Third Party Advisory
- https://github.com/zstackio/zstack/security/advisories/GHSA-jfvq-548h-342xThird Party Advisory
- https://securitylab.github.com/advisories/GHSL-2021-087-zstack/Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.