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Vulnerability record · CVE-2021-30860 · published 24 August 2021

CVE-2021-30860: Apple PDF integer overflow allows arbitrary code execution

Apple · Ipados

An integer overflow in PDF processing was fixed by improved input validation in Apple iOS, iPadOS, macOS, watchOS and related PDF libraries (xpdf, poppler). Processing a maliciously crafted PDF can lead to arbitrary code execution. Apple stated it was aware of a report that this issue may have been actively exploited.

7.8 CVSS 3.1 High CISA KEV since 3 Nov 2021 EPSS 76% · top 0.5% CWE-190 · Integer overflow
7.8CVSS 3.1 base score, v2 6.8
76%EPSS exploitation probability, 30 days
YesIn CISA KEV, fix deadline passed
7Affected product versions listed by NVD
31References
17 Jun 2026Last modified by NVD

Description

An integer overflow was addressed with improved input validation. This issue is fixed in Security Update 2021-005 Catalina, iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6, watchOS 7.6.2. Processing a maliciously crafted PDF may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 17 September 2026. Confidence: high.

critical priorityIt is listed in CISA KEV as actively exploited, has a very high EPSS score, and enables arbitrary code execution with high impact across widely deployed Apple platforms.

What it is

An integer overflow in PDF processing was fixed by improved input validation in Apple iOS, iPadOS, macOS, watchOS and related PDF libraries (xpdf, poppler). Processing a maliciously crafted PDF can lead to arbitrary code execution. Apple stated it was aware of a report that this issue may have been actively exploited.

Impact

An attacker who gets a victim to open a crafted PDF can execute arbitrary code in the context of the affected application, with high confidentiality, integrity and availability impact.

Attack surface

Reached locally by processing a malicious PDF file; the CVSS vector requires user interaction (UI:R) and no privileges (PR:N), so the victim must open or preview the crafted document.

Exploitation

CISA KEV lists it as actively exploited with a 2021-11-17 remediation due date, and EPSS is 0.75994 (99.5th percentile); references are vendor advisories and third-party mailing lists, with no public exploit code tags.

What to do

  • Apply the vendor updates: iOS 14.8/iPadOS 14.8, macOS Big Sur 11.6, Security Update 2021-005 Catalina, watchOS 7.6.2, and patched xpdf/poppler builds.
  • Block or strip PDF attachments at email and web gateways where business use allows.
  • Disable automatic PDF preview and rendering in mail clients and browsers.
  • Treat unsolicited PDFs as untrusted and require user confirmation before opening.
  • Track KEV remediation due dates and verify patched versions across Apple and Linux PDF library deployments.

Detection

  • Hunt for processes such as Preview, Quick Look, Safari, Mail or PDF readers spawning unexpected child processes or shells after opening a PDF.
  • Monitor for crashes or abnormal terminations in PDF rendering processes that correlate with recently received documents.
  • Alert on PDF files delivered as email attachments or downloads that are immediately opened by a user.
  • Review endpoint telemetry for code execution originating from PDF viewer processes outside their normal module set.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.

Exploitation in the wild

CISA added CVE-2021-30860 to the Known Exploited Vulnerabilities catalog on 3 November 2021 as "Apple Multiple Products Integer Overflow Vulnerability". Required action: Apply updates per vendor instructions. Federal deadline 17 November 2021.

Affected products

7 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://seclists.org/fulldisclosure/2021/Sep/25 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/26 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/27 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/28 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/38 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/39 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/40 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/50 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2022/09/02/11 Mailing List
https://security.gentoo.org/glsa/202209-21 Third Party Advisory
https://support.apple.com/en-us/HT212804 Vendor Advisory
https://support.apple.com/en-us/HT212805 Vendor Advisory
https://support.apple.com/en-us/HT212806 Vendor Advisory
https://support.apple.com/en-us/HT212807 Vendor Advisory
https://support.apple.com/kb/HT212824 Vendor Advisory
http://seclists.org/fulldisclosure/2021/Sep/25 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/26 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/27 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/28 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/38 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/39 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/40 Mailing ListThird Party Advisory
http://seclists.org/fulldisclosure/2021/Sep/50 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2022/09/02/11 Mailing List
https://security.gentoo.org/glsa/202209-21 Third Party Advisory
https://support.apple.com/en-us/HT212804 Vendor Advisory
https://support.apple.com/en-us/HT212805 Vendor Advisory
https://support.apple.com/en-us/HT212806 Vendor Advisory
https://support.apple.com/en-us/HT212807 Vendor Advisory
https://support.apple.com/kb/HT212824 Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30860 US Government Resource

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Source: NIST National Vulnerability Database (record CVE-2021-30860), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.