CVE-2021-30471Public exploit

Application crash via unbounded name-tree recursion

Published May 26, 2021 · Updated Aug 3, 2024

Uncontrolled recursion in PdfNamesTree::AddToDictionary in PoDoFo 0.9.7 allows context-dependent attackers to crash applications via a crafted PDF. The function follows each Kids reference and calls itself again without limiting traversal depth or detecting reference cycles. An application must process the file; recursive traversal then exhausts its thread stack and interrupts that application.

CVSS severity5.5
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled recursion in PdfNamesTree::AddToDictionary in PoDoFo 0.9.7 allows context-dependent attackers to crash applications via a crafted PDF. The function follows each Kids reference and calls itself again without limiting traversal depth or detecting reference cycles. An application must process the file; recursive traversal then exhausts its thread stack and interrupts that application.

The record

CVE
CVE-2021-30471
Published
May 26, 2021
Updated
Aug 3, 2024
Vendor
PoDoFo Project
Product
PoDoFo
Classifications
CWE-674, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=PoDoFo 0.9.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

PoDoFo Project · PoDoFoversion=PoDoFo 0.9.7

Published CVSS scores

4.3NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 exploitPublished

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1204.002Malicious File

Public exploit references

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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