CVE-2021-34971

Code execution via miscalculated JPEG2000 buffer write

Published May 7, 2024 · Updated Aug 4, 2024

Heap-based buffer overflow in Foxit PDF Reader and PDF Editor through 11.0.1 allows remote attackers to execute code via a crafted PDF. The JPEG2000 parser calculates the wrong destination region, then writes attacker-controlled data outside the intended heap buffer. Exploitation requires the target to open a malicious file or visit a malicious page, and successful code runs in the current process context.

CVSS severity7.8
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Foxit PDF Reader and PDF Editor through 11.0.1 allows remote attackers to execute code via a crafted PDF. The JPEG2000 parser calculates the wrong destination region, then writes attacker-controlled data outside the intended heap buffer. Exploitation requires the target to open a malicious file or visit a malicious page, and successful code runs in the current process context.

The record

CVE
CVE-2021-34971
Published
May 7, 2024
Updated
Aug 4, 2024
Vendor
Foxit Software
Product
Foxit PDF Reader
Classifications
CWE-122, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 7, 2024CVE 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=0 <=11.0.1.49983
  2. Affected versionversion=11.0.1.49938

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Foxit Software · Foxit PDF Readerversion=0 <=11.0.1.49983; version=11.0.1.49938
Foxit Software · Foxit PDF Editorversion=0 <=10.1.5.37672; version=0 <=11.0.0.49983; version=0 <=11.0.1.4938

Published CVSS scores

7.8Zero Day InitiativeCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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-122Heap-based Buffer Overflow
T1203Exploitation for Client Execution

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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