CVE-2021-32829 Post-authentication Remote Code Execution (RCE) in ZStack REST API
Authenticated attackers can execute arbitrary code by bypassing the Groovy sandbox in the ZStack REST API batch-query endpoint.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-32829?
CVE-2021-32829 is a critical code injection vulnerability in zstackio zstack, published on 17 Aug 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
ZStack is open source IaaS(infrastructure as a service) software aiming to automate datacenters, managing resources of compute, storage, and networking all by APIs. Affected versions of ZStack REST API are vulnerable to post-authentication Remote Code Execution (RCE) via bypass of the Groovy shell sandbox. The REST API exposes the GET zstack/v1/batch-queries?script endpoint which is backed up by the BatchQueryAction class. Messages are represented by the APIBatchQueryMsg, dispatched to the QueryFacadeImpl facade and handled by the BatchQuery class. The HTTP request parameter script is mapped to the APIBatchQueryMsg.script property and evaluated as a Groovy script in BatchQuery.query the evaluation of the user-controlled Groovy script is sandboxed by SandboxTransformer which will apply the restrictions defined in the registered (sandbox.register()) GroovyInterceptor. Even though the sandbox heavily restricts the receiver types to a small set of allowed types, the sandbox is non effective at controlling any code placed in Java annotations and therefore vulnerable to meta-programming escapes. This issue leads to post-authenticated remote code execution. For more details see the referenced GHSL-2021-065. This issue is patched in versions 3.8.21, 3.10.8, and 4.1.0.
Which versions are affected by CVE-2021-32829?
It affects 1 product.
Products include Zstack Rest Api.
How do I fix CVE-2021-32829?
No fix has been published for CVE-2021-32829 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2021-32829 being exploited?
There is no known exploitation of CVE-2021-32829 in the wild and no public exploit code.
Sources
Also known as GHSA-3q79-gjf7-rwwf.