What is the CVSS score of CVE-2021-47827?

CVE-2021-47827 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2021-47827?

Yes, a public proof-of-concept exploit is available for CVE-2021-47827. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2021-47827?

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

CVE-2021-47827

HIGH

Improper Validation of Specified Quantity in Input (CWE-1284)

2026-01-16 disclosure@vulncheck.com

Denial Of Service

7.5

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-1284 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V2 - Validation and Business Logic Input size validation
Impact	CVSS 7.5 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: None. Public exploit/POC available.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to crash the application by pasting malformed input.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

mashREPL tool contains a vulnerability that allows attackers to crash the application by pasting malformed input (CVSS 7.5).

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

Affected ProductsAI

Product: mashREPL tool.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

affects mashREPL tool. 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.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

PoC Detected

Jan 26, 2026 - 15:05 vuln.today

Public exploit code

CVE Published

Jan 16, 2026 - 19:16 nvd

HIGH 7.5

DescriptionCVE.org

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.

Executive ViewAI

Why It Matters

Organizations using WebSSH for iOS 14.16.10 face notable risk from CVE-2021-47827 rated CVSS 7.5. Exploitation could compromise the security of affected deployments. Proof-of-concept code is publicly available, increasing the risk of exploitation. Organizations should apply vendor updates when available and consider compensating controls in the interim.

Business Impact: High

Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Implement network-level access controls to limit exposure; (2) Enable enhanced monitoring and alerting; (3) Apply principle of least privilege.

Threat Intelligence Overview

EPSS Score

0.0%

Top 98% exploitable

Exploit

POC

Public exploit code exists

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS

Exploit-DB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.