How severe is CVE-2021-42559?

CVE-2021-42559 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-2021-42559 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42559?

CVE-2021-42559 affects Mitre Caldera. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42559?

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-2021-42559 published?

CVE-2021-42559 was published on 2022-01-12 and last updated on 2026-06-17.

CVE-2021-42559

CVE-2021-42559 is a high-severity vulnerability in Mitre Caldera with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-77.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-77
Affected product: Mitre Caldera
Published: 2022-01-12
Last modified: 2026-06-17

Description

An issue was discovered in CALDERA 2.8.1. It contains multiple startup "requirements" that execute commands when starting the server. Because these commands can be changed via the REST API, an authenticated user can insert arbitrary commands that will execute when the server is restarted.

Frequently asked questions

What is CVE-2021-42559?: An issue was discovered in CALDERA 2.8.1. It contains multiple startup "requirements" that execute commands when starting the server. Because these commands can be changed via the REST API, an authenticated user can insert arbitrary commands that will execute when the server is restarted.
How severe is CVE-2021-42559?: CVE-2021-42559 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-2021-42559 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42559?: CVE-2021-42559 affects Mitre Caldera. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42559?: 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-2021-42559 published?: CVE-2021-42559 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-2021-42561 — High (CVSS 8.8): An issue was discovered in CALDERA 2.8.1. When activated, the Human plugin passes the unsanitized name parameter to a…
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…

All CVEs affecting Mitre Caldera →

Other CWE-77 (Command Injection) vulnerabilities

CVE-2026-23652 — Critical (CVSS 10.0): Improper neutralization of special elements used in a command ('command injection') in Microsoft Power Pages allows an…
CVE-2025-59818 — Critical (CVSS 10.0): This vulnerability allows authenticated attackers to execute arbitrary commands on the underlying system using the file…
CVE-2025-64093 — Critical (CVSS 10.0): Remote Code Execution vulnerability that allows unauthenticated attackers to inject arbitrary commands into the…
CVE-2025-64090 — Critical (CVSS 10.0): This vulnerability allows authenticated attackers to execute commands via the hostname of the device.
CVE-2025-61492 — Critical (CVSS 10.0): A command injection vulnerability in the execute_command function of terminal-controller-mcp 0.1.7 allows attackers to…
CVE-2025-10035 — Critical (CVSS 10.0): A deserialization vulnerability in the License Servlet of Fortra's GoAnywhere MFT allows an actor with a validly forged…

Browse all CWE-77 (Command Injection) vulnerabilities →