CVE-2021-30888Network attack vector

Information disclosure via CSP report redirect behavior

Published Aug 24, 2021 · Updated Aug 3, 2024

Information disclosure in WebKit in Apple iOS, iPadOS, and macOS allows remote attackers to leak data through CSP reports. Apple states that CSP report redirect behavior leaks information but has not published the affected WebKit function or the precise data exposed. Exposure requires a user to load attacker-controlled web content; published impact is limited to information disclosure, with no integrity or availability effect.

CVSS severity7.4
High
EPSS probability1.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in WebKit in Apple iOS, iPadOS, and macOS allows remote attackers to leak data through CSP reports. Apple states that CSP report redirect behavior leaks information but has not published the affected WebKit function or the precise data exposed. Exposure requires a user to load attacker-controlled web content; published impact is limited to information disclosure, with no integrity or availability effect.

The record

CVE
CVE-2021-30888
Published
Aug 24, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-601, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 <14.8
  2. Affected versionversion=unspecified <15.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <14.8; version=unspecified <15.1
Apple · macOSversion=unspecified <12.0; version=unspecified <15.1; version=unspecified <8.1

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N
7.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')
T1189Drive-by Compromise

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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