How severe is CVE-2021-47827?

CVE-2021-47827 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-47827 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47827?

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.

Does CVE-2021-47827 have an EU (EUVD) identifier?

Yes. CVE-2021-47827 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2899.

When was CVE-2021-47827 published?

CVE-2021-47827 was published on 2026-01-16 and last updated on 2026-06-17.

CVE-2021-47827

CVE-2021-47827 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. 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-1284.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 4.6
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2899
Weakness: CWE-1284
Published: 2026-01-16
Last modified: 2026-06-17

Description

WebSSH for iOS 14.16.10 contains a denial of service vulnerability in the mashREPL tool that allows attackers to crash the application by pasting malformed input. Attackers can trigger the vulnerability by copying a 300-character buffer of repeated 'A' characters into the mashREPL input field, causing the application to crash.

Frequently asked questions

What is CVE-2021-47827?: WebSSH for iOS 14.16.10 contains a denial of service vulnerability in the mashREPL tool that allows attackers to crash the application by pasting malformed input. Attackers can trigger the vulnerability by copying a 300-character buffer of repeated 'A' characters into the mashREPL input field, causing the application to crash.
How severe is CVE-2021-47827?: CVE-2021-47827 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-47827 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47827?: 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.
Does CVE-2021-47827 have an EU (EUVD) identifier?: Yes. CVE-2021-47827 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2899.
When was CVE-2021-47827 published?: CVE-2021-47827 was published on 2026-01-16 and last updated on 2026-06-17.

References

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