CVE-2021-47827Public exploit

Application crash via oversized mashREPL input

Published Jan 16, 2026 · Updated Jan 16, 2026

Denial of service in mashREPL in WebSSH for iOS 14.16.10 allows attackers to crash the application by pasting oversized input. The mashREPL input field accepts a 300-character string of repeated A characters without correctly validating its length and terminates when submitted. Exploitation requires an iOS user to place the crafted text on the clipboard, open mashREPL, paste the text, and submit it; only the WebSSH process crashes.

CVSS severity4.6
Medium
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in mashREPL in WebSSH for iOS 14.16.10 allows attackers to crash the application by pasting oversized input. The mashREPL input field accepts a 300-character string of repeated A characters without correctly validating its length and terminates when submitted. Exploitation requires an iOS user to place the crafted text on the clipboard, open mashREPL, paste the text, and submit it; only the WebSSH process crashes.

The record

CVE
CVE-2021-47827
Published
Jan 16, 2026
Updated
Jan 16, 2026
Vendor
Huashengdun
Product
WebSSH
Classifications
CWE-1284, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=14.16.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Huashengdun · WebSSHversion=14.16.10

Published CVSS scores

4.6VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
7.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1284Improper Validation of Specified Quantity in Input
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

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Technologies

Your stack

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Your stack

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