CVE-2021-25281 — salt
CRITICALCVE-2021-25281 is a critical-severity (CVSS 9.8) Improper Authentication vulnerability in salt. 5 public exploit references exist, so weaponization risk is real. A fix is available for salt — see the affected versions and patch details below.
SaltStack Salt Improper Authentication vulnerability
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2021-25281.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2021-25281 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
salt🐍salt🐍salt🐍salt🐍salt🐍salt🐍salt🐍salt+1 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | salt | all versions | 2015.8.13pip install --upgrade 'salt==2015.8.13' |
| 🐍PyPI | salt | ≥ 2016.3.0&&< 2016.11.5 | 2016.11.5pip install --upgrade 'salt==2016.11.5' |
| 🐍PyPI | salt | ≥ 2016.11.7&&< 2016.11.10 | 2016.11.10pip install --upgrade 'salt==2016.11.10' |
| 🐍PyPI | salt | ≥ 2017.5.0&&< 2017.7.8 | 2017.7.8pip install --upgrade 'salt==2017.7.8' |
| 🐍PyPI | salt | ≥ 2018.2.0 | No fix |
| 🐍PyPI | salt | ≥ 2019.2.0&&< 2019.2.8 | 2019.2.8pip install --upgrade 'salt==2019.2.8' |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
An issue was discovered in through SaltStack Salt before 3002.5. salt-ap…
An issue was discovered in through SaltStack Salt before 3002.5. salt-ap…
An issue was discovered in through SaltStack Salt before 3002.5. salt-ap…
An issue was discovered in through SaltStack Salt before 3002.5. salt-ap…
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for salt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update salt to 2015.8.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25281 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2021-25281 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-25281. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2021-25281
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2021-25281 -u https://target- Template
- SaltStack Salt <3002.5 - Auth Bypass
- Severity
- critical
- Impact
- Unauthenticated attackers can remotely execute any wheel modules on the Salt master by bypassing eauth credentials, leading to complete infrastructure compromise and control over all managed systems.
- Remediation
- Upgrade to SaltStack Salt version 3002.5 or later to mitigate this vulnerability.
Template by ProjectDiscovery nuclei-templates (madrobot), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2021-25281 in your dependencies?
O3 Security finds CVE-2021-25281 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.