CVE-2023-27961

User-information exfiltration via unsanitized calendar invitation

Published May 8, 2023 · Updated Jan 29, 2025

Improper input validation in Calendar on affected Apple platforms allows attackers to exfiltrate user information through a crafted invitation. The Calendar invitation importer processes attacker-controlled event data without the input sanitization required to prevent disclosure. A person must import the invitation; Apple has not disclosed the specific user information exposed or the exact validation paths involved.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Calendar on affected Apple platforms allows attackers to exfiltrate user information through a crafted invitation. The Calendar invitation importer processes attacker-controlled event data without the input sanitization required to prevent disclosure. A person must import the invitation; Apple has not disclosed the specific user information exposed or the exact validation paths involved.

The record

CVE
CVE-2023-27961
Published
May 8, 2023
Updated
Jan 29, 2025
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-20, CWE-1284, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 29, 2025Record 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 <15.7
  2. Affected versionversion=unspecified <16.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <15.7; version=unspecified <16.4
Apple · macOSversion=unspecified <11.7; version=unspecified <12.6; version=unspecified <13.3
Apple · watchOSversion=unspecified <9.4

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-1284Improper Validation of Specified Quantity in Input
T1204.002User Execution: Malicious File

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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