CVE-2021-33480Public exploit

Process crash via freed box dereference

Published Nov 17, 2021 · Updated Aug 3, 2024

Use-after-free in GOCR 0.53-20200802 allows context-dependent attackers to crash the OCR process via crafted image input. In pgm2asc.c, context_correction reads a box field after free_box releases the heap allocation containing it. Exploitation requires a user or local workflow to run GOCR in mode 4 on attacker-supplied input, causing the process to abort.

CVSS severity5.5
Medium
EPSS probability1.08%
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 GOCR 0.53-20200802 allows context-dependent attackers to crash the OCR process via crafted image input. In pgm2asc.c, context_correction reads a box field after free_box releases the heap allocation containing it. Exploitation requires a user or local workflow to run GOCR in mode 4 on attacker-supplied input, causing the process to abort.

The record

CVE
CVE-2021-33480
Published
Nov 17, 2021
Updated
Aug 3, 2024
Vendor
GOCR Project
Product
GOCR
Classifications
CWE-416, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 17, 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=gocr 0.53-20200802

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

GOCR Project · GOCRversion=gocr 0.53-20200802

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
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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