What is the CVSS score of CVE-2021-32829?

CVE-2021-32829 has a CVSS 3.1 base score of 9.9 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 2.9%.

Is there a public PoC exploit available for CVE-2021-32829?

Yes, a public proof-of-concept exploit is available for CVE-2021-32829. Prioritise patching immediately. EPSS: 2.9%.

Java CVE-2021-32829

CRITICAL

Code Injection (CWE-94)

2021-08-17 security-advisories@github.com

RCE Code Injection Java Rest Api

9.9

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.9 CRITICAL

AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Aug 17, 2021 - 16:15 nvd

CRITICAL 9.9

DescriptionNVD

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.

AnalysisAI

ZStack is open source IaaS(infrastructure as a service) software aiming to automate datacenters, managing resources of compute, storage, and networking all by APIs. Rated critical severity (CVSS 9.9), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Code Injection (CWE-94), which allows attackers to inject and execute arbitrary code within the application. 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. Affected products include: Zstack Rest Api.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Never evaluate user-controlled input as code. Use sandboxing, disable dangerous functions, apply strict input validation.