CVE-2020-29639

Process-memory disclosure via FontParser out-of-bounds read

Published Apr 2, 2021 · Updated Aug 4, 2024

An out-of-bounds read in Apple iOS and iPadOS before 14.0 allows attackers to disclose process memory through a malicious font. The FontParser component insufficiently validates font input before reading beyond the intended buffer boundary. The target must process the crafted font, and the documented effect is limited to disclosure of memory from the affected process.

CVSS severity5.5
Medium
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds read in Apple iOS and iPadOS before 14.0 allows attackers to disclose process memory through a malicious font. The FontParser component insufficiently validates font input before reading beyond the intended buffer boundary. The target must process the crafted font, and the documented effect is limited to disclosure of memory from the affected process.

The record

CVE
CVE-2020-29639
Published
Apr 2, 2021
Updated
Aug 4, 2024
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-125
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 2, 2021CVE 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 <14.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <14.0

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:P/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.

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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-125Out-of-bounds Read

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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