CVE-2021-34948

Code execution via Square annotation use-after-free

Published May 7, 2024 · Updated Aug 4, 2024

Use-after-free in affected Foxit PDF Reader and PDF Editor releases allows remote attackers to execute code via a crafted PDF. Square annotation handling operates on an object without first verifying that the object still exists after its storage has been freed. Exploitation requires a user to visit a malicious page or open a malicious PDF, and successful execution inherits the current process context.

CVSS severity7.8
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in affected Foxit PDF Reader and PDF Editor releases allows remote attackers to execute code via a crafted PDF. Square annotation handling operates on an object without first verifying that the object still exists after its storage has been freed. Exploitation requires a user to visit a malicious page or open a malicious PDF, and successful execution inherits the current process context.

The record

CVE
CVE-2021-34948
Published
May 7, 2024
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. 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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
  2. Affected versionversion=- <=11.0.1.49938

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Foxit Software · Foxit PDF Readerversion=11.0.0.49893; version=- <=11.0.1.49938
Foxit Software · Foxit PDF Editorversion=- <=10.1.5.37672; version=11.0.0.49893; version=11.0.1.49938

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

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo