CVE-2019-20633Public exploit

Utility crash via double free in another_hunk

Published Mar 25, 2020 · Updated Aug 5, 2024

Double free in GNU patch 2.7.6 and earlier allows local users to crash the utility by supplying a crafted patch file. In another_hunk in pch.c, crafted context-format input drives the cleanup loop to call free(p_line[p_end]) twice for the same allocation. Execution requires a user or automated workflow to process the malicious file; the documented consequence is a process crash, not code execution.

CVSS severity5.5
Medium
EPSS probability1.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in GNU patch 2.7.6 and earlier allows local users to crash the utility by supplying a crafted patch file. In another_hunk in pch.c, crafted context-format input drives the cleanup loop to call free(p_line[p_end]) twice for the same allocation. Execution requires a user or automated workflow to process the malicious file; the documented consequence is a process crash, not code execution.

The record

CVE
CVE-2019-20633
Published
Mar 25, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-415
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 25, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5Canonical UbuntuCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
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 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-415Double Free

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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