CRITICAL

CVE-2021-21877

CVSS v3

9.1

CRITICAL

EPSS Score

2.8 %

exploit probability, as of 2026-10-20

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2021-21877 yet.

Full record on NVD

Description

Specially-crafted HTTP requests can lead to arbitrary command execution in “GET” requests. An attacker can make authenticated HTTP requests to trigger this vulnerability.

Technical details

Published: 2021-12-22

Frequently asked questions

What is CVE-2021-21877?

Specially-crafted HTTP requests can lead to arbitrary command execution in “GET” requests. An attacker can make authenticated HTTP requests to trigger this vulnerability.

Is CVE-2021-21877 actively exploited?

Active exploitation of CVE-2021-21877 has not been confirmed. Its EPSS score was 2.8% on 2026-10-20, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-21877?

CVE-2021-21877 has a CVSS v3 base score of 9.1 (CRITICAL severity).

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