# CVE-2021-25281: SaltStack - Authentication Bypass

> Live exploitation tracking for CVE-2021-25281 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-2021-25281

## 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:** SaltStack
- **Weaknesses:** CWE-287 (Improper Authentication)
- **Tags:** enterprise_software

## Description

An issue was discovered in through SaltStack Salt before 3002.5. salt-api does not honor eauth credentials for the wheel_async client. Thus, an attacker can remotely run any wheel modules on the master.

## CrowdSec analysis

[CVE-2021-25281](https://euvd.enisa.europa.eu/vulnerability/CVE-2021-25281) is a critical vulnerability in SaltStack Salt before version 3002.5, where the salt-api fails to enforce eauth credentials for the wheel_async client. This flaw allows remote attackers to execute arbitrary wheel modules on the Salt master, potentially leading to full system compromise.

CrowdSec has been tracking this vulnerability and its exploits since 7th of January 2026.

Data from the CrowdSec community indicates that exploitation of CVE-2021-25281 is highly selective and intelligence-driven. Threat actors use advanced reconnaissance and carefully choose their targets, often as part of sophisticated campaigns or advanced persistent threat operations.
Data from the CrowdSec community also indicates a gradual decrease in attacks targeting CVE-2021-25281. While still present in the wild, exploitation levels have dropped noticeably week-over-week. This may signal that the vulnerability is becoming less relevant or that defenses are improving fast enough for attackers to lose interest.

Attackers exploit this vulnerability by sending unauthenticated POST requests to the `/run` endpoint with a JSON body specifying the `client` parameter as `wheel_async`, allowing them to bypass authentication and execute arbitrary wheel modules on the Salt master.

## Timeline

- 2021-02-27: CVE Published. CVE-2021-25281 is published to NVD.
- 2026-01-07: Rule Released. CrowdSec releases a rule to detect CVE-2021-25281 exploitation attempts against the CrowdSec Network.
- 2026-01-14: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2021-25281 for the first time.

## References

- https://github.com/saltstack/salt/releases
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FUGLOJ6NXLCIFRD2JTXBYQEMAEF2B6XH/
- https://www.debian.org/security/2021/dsa-5011
- https://security.gentoo.org/glsa/202103-01
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YOGNT2XWPOYV7YT75DN7PS4GIYWFKOK5/
- https://lists.debian.org/debian-lts-announce/2021/11/msg00009.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7GRVZ5WAEI3XFN2BDTL6DDXFS5HYSDVB/
- http://packetstormsecurity.com/files/162058/SaltStack-Salt-API-Unauthenticated-Remote-Command-Execution.html
- https://security.gentoo.org/glsa/202310-22
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-25281.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2021-25281) follows observed exploitation activity for CVE-2021-25281. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.