# CVE-2021-34427: Eclipse BIRT - RCE

> Live exploitation tracking for CVE-2021-34427 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-2021-34427

## Key facts

- **Exploitation phase:** Background Noise. Continuous low-level scanning or exploitation attempts are observed, mostly opportunistic and automated.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** The Eclipse Foundation Eclipse BIRT
- **Weaknesses:** CWE-20 (Improper Input Validation); CWE-434 (Unrestricted Upload of File with Dangerous Type)
- **Tags:** enterprise_software

## Description

In Eclipse BIRT versions 4.8.0 and earlier, an attacker can use query parameters to create a JSP file which is accessible from remote (current BIRT viewer dir) to inject JSP code into the running instance.

## CrowdSec analysis

[CVE-2021-34427](https://euvd.enisa.europa.eu/vulnerability/CVE-2021-34427) is a critical vulnerability in Eclipse BIRT versions 4.8.0 and earlier that allows remote attackers to inject malicious JSP code by manipulating query parameters. Exploiting this flaw could enable attackers to execute arbitrary code on the server, potentially leading to full system compromise and unauthorized access to sensitive data.

CrowdSec has been tracking this vulnerability and its exploits since 10th of December 2025.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2021-34427 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning.
Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2021-34427 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2021-34427 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Attackers exploit this vulnerability by sending crafted requests to the `/document` endpoint with malicious query parameters, resulting in the creation and execution of attacker-controlled JSP files within the application directory. Subsequent requests to the uploaded `.jsp` files are used to execute arbitrary code on the server.

## Timeline

- 2021-06-25: CVE Published. CVE-2021-34427 is published to NVD.
- 2025-12-10: Rule Released. CrowdSec releases a rule to detect CVE-2021-34427 exploitation attempts against the CrowdSec Network.
- 2025-12-16: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2021-34427 for the first time.

## References

- http://seclists.org/fulldisclosure/2022/Dec/30
- http://packetstormsecurity.com/files/170326/Eclipse-Business-Intelligence-Reporting-Tool-4.11.0-Remote-Code-Execution.html
- https://bugs.eclipse.org/bugs/show_bug.cgi?id=538142
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-34427.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2021-34427) follows observed exploitation activity for CVE-2021-34427. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.