CVE-2021-44657Public exploitNetwork attack vector

Authenticated command execution via unsandboxed Jinja templates

Published Dec 15, 2021 · Updated Aug 4, 2024

Template injection in StackStorm before 3.6.0 allows remote authenticated users to execute system commands through crafted Jinja templates. The template rendering environment used Jinja's ordinary Environment rather than SandboxedEnvironment, permitting object traversal and Python function calls from template content. Exploitation requires a StackStorm login through the CLI, API, Web UI, or workflows; no unauthenticated path is reported.

CVSS severity8.8
High
EPSS probability2.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Template injection in StackStorm before 3.6.0 allows remote authenticated users to execute system commands through crafted Jinja templates. The template rendering environment used Jinja's ordinary Environment rather than SandboxedEnvironment, permitting object traversal and Python function calls from template content. Exploitation requires a StackStorm login through the CLI, API, Web UI, or workflows; no unauthenticated path is reported.

The record

CVE
CVE-2021-44657
Published
Dec 15, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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