CVE-2022-33891: Apache Spark Command Injection Vulnerability

CVE-2022-33891 is a command injection vulnerability in Apache Spark that can be reached through the Spark User Interface (UI) when Access Control Lists (ACLs) are enabled. An attacker who can interact with that interface may be able to inject and run operating-system commands on the host running the Spark UI. Because Spark is commonly used for large-scale data processing, successful abuse can give an adversary a foothold inside analytics or data-platform environments. Exact impact depends on how the UI is exposed and what privileges the Spark process holds; teams should treat any internet-facing or poorly segmented Spark UI as high priority for review.

CISA lists the required action as applying updates per the vendor’s instructions. Public detail on versions, scores, and exploit mechanics is limited to the summary above; confirm all specifics against the official Apache Spark advisory before acting.

How it works

The weakness is classified as CWE-78 (OS Command Injection). In this class of flaw, user-controlled input is passed to a system shell or command interpreter without sufficient sanitization or parameterization. When ACLs are enabled on the Spark UI, the interface accepts certain inputs that the backend ultimately uses in a way that can reach a command execution path. An attacker who can reach the UI and craft a malicious request may therefore cause the Spark process to run arbitrary commands under the privileges of that process.

No public exploit code or detailed request format is supplied in the available facts. Defenders should assume that any authenticated or unauthenticated access to the Spark UI (depending on the deployment’s ACL and authentication configuration) could be abused until the vendor patch is applied and the configuration is verified. Confirm the precise trigger conditions and fixed behavior against the Apache Spark security advisory.

Am I affected? How to find it in your systems

Apache Spark is typically deployed in data-engineering, analytics, and machine-learning clusters—on-premises, in cloud VMs, or inside container platforms. The Spark UI (often listening on a well-known HTTP port such as 4040 or a configured alternative) is the component named in the vulnerability description. Look for running Spark masters, workers, or history servers that expose a web UI and that have ACLs turned on.

• Inventory: search configuration management databases, container registries, Kubernetes deployments, and host package lists for Apache Spark installations. Query process lists and listening ports for the Spark UI service.
• Configuration check: examine spark-defaults.conf, spark-env.sh, and any ACL-related properties (for example those controlling authentication or authorization for the UI). Confirm whether ACLs are enabled; the vulnerability is described as present when they are.
• Version and patch status: record the exact Spark version in use and compare it with the fixed versions listed in the vendor advisory. Do not rely on version numbers not published by Apache.
• Telemetry and logs: review Spark UI access logs, reverse-proxy or load-balancer logs, and host process-creation events for unexpected command execution or anomalous requests targeting the UI. Look for spikes in failed or unusual HTTP requests to the UI path around the time of any suspected activity.

If the UI is reachable from untrusted networks or if ACLs are enabled without compensating controls, treat the instance as potentially affected until proven otherwise.

How to remediate

Patch first. Apply the Apache Spark updates that address CVE-2022-33891 exactly as directed in the vendor advisory. After installing the update, restart the affected Spark services and verify that the UI still functions as expected under your ACL configuration.

• Validate the fix by confirming the installed package or container image matches the patched release and by re-checking the configuration that previously enabled ACLs.
• Harden the deployment: restrict network access to the Spark UI to management networks only, enforce strong authentication in front of the UI, and run the Spark process under a least-privilege account that cannot perform unnecessary system actions.
• Review any custom scripts or job-submission paths that interact with the UI to ensure they do not re-introduce unsanitized input.

Document the change and update your vulnerability-management records so future scans correctly mark the asset as remediated.

If you can't patch immediately

Until the vendor update can be applied, reduce exposure with compensating controls that limit reachability and detect abuse.

• Network segmentation: place the Spark UI behind a firewall or security group that allows access only from trusted administrative jump hosts or bastion networks. Block direct internet or broad internal access.
• Virtual patching / WAF: if a reverse proxy or web application firewall sits in front of the UI, add rules that reject or sanitize unexpected characters and request patterns commonly associated with command-injection attempts. Test rules carefully to avoid breaking legitimate UI functionality.
• Feature reduction: where operationally feasible, temporarily disable the Spark UI or turn off ACLs only if doing so does not create a larger security gap; consult the vendor documentation before changing ACL settings.
• Monitoring: enable detailed access logging on the UI and forward those logs to a SIEM. Alert on anomalous request volumes, unusual user agents, or host-level process creation originating from the Spark service account. Increase host-based detection for shell spawning by the Spark process.

These measures lower risk but do not replace the official patch. Schedule the update as soon as change windows allow.

If your data may have been exposed

Actively exploited command-injection flaws can lead to full host compromise and subsequent data theft or ransomware deployment; however, known ransomware use of this specific CVE is not documented in the available facts. If you discover evidence of exploitation—unexpected processes, outbound connections, or data exfiltration—follow your incident-response plan: isolate the host, preserve forensic artifacts, and engage your security operations team. As a routine hygiene step, you can also run a free exposure scan of organizational email addresses against known breach data sets to check whether credentials or personal information associated with your environment have already appeared in public dumps.