CVE-2021-34838

Code execution via shared Annotation dictionary reuse

Published Aug 4, 2021 · Updated Aug 4, 2024

Use-after-free in Foxit PDF Reader 11.0.0.49893 allows remote attackers to execute code through a malicious PDF or web page. Multiple Annotation objects can reference the same Annotation dictionary, leaving the application to operate on an object after its memory has been freed. Exploitation requires the target to open the file or visit the page, and resulting code runs in the Reader process context.

CVSS severity7.8
High
EPSS probability3.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Foxit PDF Reader 11.0.0.49893 allows remote attackers to execute code through a malicious PDF or web page. Multiple Annotation objects can reference the same Annotation dictionary, leaving the application to operate on an object after its memory has been freed. Exploitation requires the target to open the file or visit the page, and resulting code runs in the Reader process context.

The record

CVE
CVE-2021-34838
Published
Aug 4, 2021
Updated
Aug 4, 2024
Vendor
Foxit Software
Product
Foxit PDF Reader
Classifications
CWE-416, T1203, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 4, 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=11.0.0.49893

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Foxit Software · Foxit PDF Readerversion=11.0.0.49893

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8Zero Day InitiativeCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/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.

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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-416Use After Free
T1203Exploitation for Client Execution
T1204.002User Execution: Malicious File

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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