CVE-2020-3844

Removed-participant conversation-state modification

Published Feb 27, 2020 · Updated Aug 4, 2024

Authorization flaw in Messages on Apple iOS before 13.3.1 allows removed iMessage participants to alter conversation state. Apple has not disclosed which Messages check failed or which conversation-state operations remained available after removal. Exploitation requires prior membership in the iMessage conversation, and the established consequence is limited to modifying its state.

CVSS severity3.3
Low
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization flaw in Messages on Apple iOS before 13.3.1 allows removed iMessage participants to alter conversation state. Apple has not disclosed which Messages check failed or which conversation-state operations remained available after removal. Exploitation requires prior membership in the iMessage conversation, and the established consequence is limited to modifying its state.

The record

CVE
CVE-2020-3844
Published
Feb 27, 2020
Updated
Aug 4, 2024
Vendor
Apple
Product
iOS
Classifications
T1565
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=unspecified <iOS 13.3.1 and iPadOS 13.3.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Apple · iOSversion=unspecified <iOS 13.3.1 and iPadOS 13.3.1

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:N
3.3NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1565Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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