# CVE-2020-9480: Apache Spark - Authentication Bypass

> Live exploitation tracking for CVE-2020-9480 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2020-9480

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** Apache Spark
- **Weaknesses:** CWE-306 (Missing Authentication for Critical Function)
- **Tags:** enterprise_software, web_application

## Description

In Apache Spark 2.4.5 and earlier, a standalone resource manager's master may be configured to require authentication (spark.authenticate) via a shared secret. When enabled, however, a specially-crafted RPC to the master can succeed in starting an application's resources on the Spark cluster, even without the shared key. This can be leveraged to execute shell commands on the host machine. This does not affect Spark clusters using other resource managers (YARN, Mesos, etc).

## CrowdSec analysis

[CVE-2020-9480](https://euvd.enisa.europa.eu/vulnerability/CVE-2020-9480) is a critical vulnerability in Apache Spark 2.4.5 and earlier that allows unauthenticated attackers to bypass authentication on standalone resource manager masters. By sending specially-crafted RPC requests, attackers can start application resources and execute arbitrary shell commands on the host machine, potentially leading to full system compromise. This issue does not affect Spark clusters managed by YARN, Mesos, or other resource managers.

CrowdSec has been tracking this vulnerability and its exploits since 15th of October 2025.

CrowdSec network observations suggest that most exploitation of CVE-2020-9480 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental.
CrowdSec data also reveals a clear uptick in attacks involving CVE-2020-9480 over the past week. Activity is above the usual baseline, suggesting growing attention from attackers. This may reflect rising awareness, recent exploit releases, or expanded targeting efforts.

Attackers exploit the Apache Spark REST API by sending crafted POST requests to the `/v1/submissions/create` endpoint, bypassing authentication to execute arbitrary commands or deploy malicious applications on the cluster. This activity targets Spark Master nodes typically running on port 6066.

## Timeline

- 2020-06-23: CVE Published. CVE-2020-9480 is published to NVD.
- 2025-10-15: Rule Released. CrowdSec releases a rule to detect CVE-2020-9480 exploitation attempts against the CrowdSec Network.
- 2025-10-24: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2020-9480 for the first time.

## References

- https://lists.apache.org/thread.html/ree9e87aae81852330290a478692e36ea6db47a52a694545c7d66e3e2%40%3Cdev.spark.apache.org%3E
- https://spark.apache.org/security.html#CVE-2020-9480
- https://lists.apache.org/thread.html/ra0e62a18ad080c4ce6df5e0202a27eaada75222761efc3f7238b5a3b%40%3Ccommits.doris.apache.org%3E
- https://lists.apache.org/thread.html/r03ad9fe7c07d6039fba9f2152d345274473cb0af3d8a4794a6645f4b%40%3Cuser.spark.apache.org%3E
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://lists.apache.org/thread.html/rb3956440747e41940d552d377d50b144b60085e7ff727adb0e575d8d%40%3Ccommits.submarine.apache.org%3E
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2020/CVE-2020-9480.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2020-9480) follows observed exploitation activity for CVE-2020-9480. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.