CVE-2021-21289Network attack vector

OS command execution via Kernel.open filename handling

Published Feb 2, 2021 · Updated Aug 3, 2024

OS command injection in Sparkle Motion Mechanize 2.0 through 2.7.6 allows remote attackers to execute commands via a crafted local filename. Several file-saving and cookie-jar methods pass attacker-controlled filename strings to Ruby Kernel.open, where a leading pipe invokes an operating-system command. Exploitation requires a consuming application to accept untrusted input as a local filename and pass it to an affected method; successful attacks run commands with that application's privileges.

CVSS severity7.4
High
EPSS probability3.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Sparkle Motion Mechanize 2.0 through 2.7.6 allows remote attackers to execute commands via a crafted local filename. Several file-saving and cookie-jar methods pass attacker-controlled filename strings to Ruby Kernel.open, where a leading pipe invokes an operating-system command. Exploitation requires a consuming application to accept untrusted input as a local filename and pass it to an affected method; successful attacks run commands with that application's privileges.

The record

CVE
CVE-2021-21289
Published
Feb 2, 2021
Updated
Aug 3, 2024
Vendor
Sparkle Motion
Product
Mechanize
Classifications
CWE-78, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.0, < 2.7.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Sparkle Motion · Mechanizeversion=>= 2.0, < 2.7.7

Published CVSS scores

7.4GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N
7.6NIST NVDAV:N/AC:H/Au:N/C:C/I:C/A:C
8.3NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

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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