CVE-2014-8139

Process crash via CRC32 length underflow

Published Jan 31, 2020 · Updated Aug 6, 2024

Heap buffer over-read in Info-ZIP UnZip 6.0 and earlier allows attackers to crash the process via a crafted ZIP file tested with -t. TestExtraField accepts an EF_PKVMS extra-block length below four and passes the underflowed ebLen-4 value to crc32, causing an extensive heap read. The affected path runs only in test mode, not during extraction, and checksum computation does not write or corrupt memory.

CVSS severity7.8
High
EPSS probability7.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer over-read in Info-ZIP UnZip 6.0 and earlier allows attackers to crash the process via a crafted ZIP file tested with -t. TestExtraField accepts an EF_PKVMS extra-block length below four and passes the underflowed ebLen-4 value to crc32, causing an extensive heap read. The affected path runs only in test mode, not during extraction, and checksum computation does not write or corrupt memory.

The record

CVE
CVE-2014-8139
Published
Jan 31, 2020
Updated
Aug 6, 2024
Vendor
Info-ZIP
Product
UnZip
Classifications
CWE-787, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 31, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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=6.0 and earlier

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Info-ZIP · UnZipversion=6.0 and earlier

Published CVSS scores

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

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-787Out-of-bounds Write
T1203Exploitation for Client Execution

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

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Your stack

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