How severe is CVE-2021-42561?

CVE-2021-42561 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42561 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42561?

CVE-2021-42561 affects Mitre Caldera. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42561?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-42561 published?

CVE-2021-42561 was published on 2022-01-12 and last updated on 2026-06-17.

CVE-2021-42561

CVE-2021-42561 is a high-severity vulnerability in Mitre Caldera with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 20% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-74.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 20% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-74
Affected product: Mitre Caldera
Published: 2022-01-12
Last modified: 2026-06-17

Description

An issue was discovered in CALDERA 2.8.1. When activated, the Human plugin passes the unsanitized name parameter to a python "os.system" function. This allows attackers to use shell metacharacters (e.g., backticks "``" or dollar parenthesis "$()" ) in order to escape the current command and execute arbitrary shell commands.

Frequently asked questions

What is CVE-2021-42561?: An issue was discovered in CALDERA 2.8.1. When activated, the Human plugin passes the unsanitized name parameter to a python "os.system" function. This allows attackers to use shell metacharacters (e.g., backticks "``" or dollar parenthesis "$()" ) in order to escape the current command and execute arbitrary shell commands.
How severe is CVE-2021-42561?: CVE-2021-42561 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42561 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42561?: CVE-2021-42561 affects Mitre Caldera. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42561?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-42561 published?: CVE-2021-42561 was published on 2022-01-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mitre:caldera:*:*:*:*:*:*:*:*

More vulnerabilities in Mitre Caldera

CVE-2021-42559 — High (CVSS 8.8): An issue was discovered in CALDERA 2.8.1. It contains multiple startup "requirements" that execute commands when…
CVE-2021-42560 — High (CVSS 8.8): An issue was discovered in CALDERA 2.9.0. The Debrief plugin receives base64 encoded "SVG" parameters when generating a…
CVE-2020-19907 — High (CVSS 8.8): A command injection vulnerability in the sandcat plugin of Caldera 2.3.1 and earlier allows authenticated attackers to…
CVE-2021-42562 — High (CVSS 8.1): An issue was discovered in CALDERA 2.8.1. It does not properly segregate user privileges, resulting in non-admin users…
CVE-2022-40606 — Medium (CVSS 6.1): MITRE CALDERA before 4.1.0 allows XSS in the Operations tab and/or Debrief plugin via a crafted operation name, a…
CVE-2022-40605 — Medium (CVSS 6.1): MITRE CALDERA before 4.1.0 allows XSS in the Operations tab and/or Debrief plugin via a crafted operation name, a…

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