How severe is CVE-2021-21431?

CVE-2021-21431 has a CVSS 3.x base score of 7.6, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-21431 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21431?

CVE-2021-21431 affects Mirahezebots Channelmgnt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21431?

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-2021-21431 published?

CVE-2021-21431 was published on 2021-04-09 and last updated on 2026-06-17.

CVE-2021-21431

CVE-2021-21431 is a high-severity vulnerability in Mirahezebots Channelmgnt with a CVSS 3.x base score of 7.6. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.6)
CVSS v2: 5.5
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Mirahezebots Channelmgnt
Published: 2021-04-09
Last modified: 2026-06-17

Description

sopel-channelmgnt is a channelmgnt plugin for sopel. In versions prior to 2.0.1, on some IRC servers, restrictions around the removal of the bot using the kick/kickban command could be bypassed when kicking multiple users at once. We also believe it may have been possible to remove users from other channels but due to the wonder that is IRC and following RfCs, We have no POC for that. Freenode is not affected. This is fixed in version 2.0.1. As a workaround, do not use this plugin on networks where TARGMAX > 1.

Frequently asked questions

What is CVE-2021-21431?: sopel-channelmgnt is a channelmgnt plugin for sopel. In versions prior to 2.0.1, on some IRC servers, restrictions around the removal of the bot using the kick/kickban command could be bypassed when kicking multiple users at once. We also believe it may have been possible to remove users from other channels but due to the wonder that is IRC and following RfCs, We have no POC for that. Freenode is not affected. This is fixed in version 2.0.1. As a workaround, do not use this plugin on networks where TARGMAX > 1.
How severe is CVE-2021-21431?: CVE-2021-21431 has a CVSS 3.x base score of 7.6, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-21431 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21431?: CVE-2021-21431 affects Mirahezebots Channelmgnt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21431?: 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-2021-21431 published?: CVE-2021-21431 was published on 2021-04-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mirahezebots:channelmgnt:*:*:*:*:*:sopel:*:*

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