# CVE-2021-31589: BeyondTrust Secure Remote Access - XSS

> Live exploitation tracking for CVE-2021-31589 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-2021-31589

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 6.1
- **Public exploit available:** Yes
- **Affected products:** BeyondTrust Secure Remote Access
- **Weaknesses:** CWE-79 (Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'))

## Description

A cross-site scripting (XSS) vulnerability has been reported and confirmed for BeyondTrust Secure Remote Access Base Software version 6.0.1 and older, which allows the injection of unauthenticated, specially-crafted web requests without proper sanitization.

## CrowdSec analysis

[CVE-2021-31589](https://euvd.enisa.europa.eu/vulnerability/CVE-2021-31589) is a cross-site scripting (XSS) vulnerability affecting BeyondTrust Secure Remote Access. It enables attackers to inject unauthenticated, specially crafted web requests through insufficient sanitization in the login interface.

CrowdSec has been tracking this vulnerability and its exploits since 31st of March 2025.

CrowdSec network observations suggest that most exploitation of CVE-2021-31589 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 network telemetry also shows that exploitation of CVE-2021-31589 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Observed exploitation attempts target URLs containing `/appliance/login.ns`.

## Timeline

- 2022-01-05: CVE Published. CVE-2021-31589 is published to NVD.
- 2025-03-31: Rule Released. CrowdSec releases a rule to detect CVE-2021-31589 exploitation attempts against the CrowdSec Network.
- 2025-04-01: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2021-31589 for the first time.

## References

- https://cxsecurity.com/issue/WLB-2022010013
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-31589.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2021-31589) follows observed exploitation activity for CVE-2021-31589. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.