CVE-2021-1807

Arbitrary file writes via insufficient input sanitization

Published Sep 8, 2021 · Updated Aug 3, 2024

Improper input validation in Safari on iOS and iPadOS before 14.5 and watchOS before 7.4 allows local users to write arbitrary files. Apple identifies the locus only as Safari and states that insufficient input sanitization permits the write; no affected function, input field, or file-path handling detail is public. Local low-privileged access is required, and the documented consequence is limited to unauthorized file writes with no reported read, execution, or service-interruption capability.

CVSS severity5.5
Medium
EPSS probability0.32%
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 Safari on iOS and iPadOS before 14.5 and watchOS before 7.4 allows local users to write arbitrary files. Apple identifies the locus only as Safari and states that insufficient input sanitization permits the write; no affected function, input field, or file-path handling detail is public. Local low-privileged access is required, and the documented consequence is limited to unauthorized file writes with no reported read, execution, or service-interruption capability.

The record

CVE
CVE-2021-1807
Published
Sep 8, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-20, T1565.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 8, 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 <14.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <14.5
Apple · watchOSversion=unspecified <7.4

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:C/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

CWE-20Improper Input Validation
T1565.001Stored Data 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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