CVE-2023-39743Public exploitNetwork attack vector

Process crash via crafted LRZ file

Published Aug 17, 2023 · Updated Oct 8, 2024

Access violation in lrzip-next LZMA 23.01 allows attackers to crash its decompression process by supplying a crafted LRZ file. The bz3_decode_block routine in src/libbz3.c reads address 0x8 from the zero page while decoding a two-byte compressed stream, triggering a segmentation fault. Exploitation requires the crafted archive to reach the bzip3 decompression path; the demonstrated consequence is a process abort, not data disclosure or modification.

CVSS severity5.3
Medium
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Access violation in lrzip-next LZMA 23.01 allows attackers to crash its decompression process by supplying a crafted LRZ file. The bz3_decode_block routine in src/libbz3.c reads address 0x8 from the zero page while decoding a two-byte compressed stream, triggering a segmentation fault. Exploitation requires the crafted archive to reach the bzip3 decompression path; the demonstrated consequence is a process abort, not data disclosure or modification.

The record

CVE
CVE-2023-39743
Published
Aug 17, 2023
Updated
Oct 8, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-284, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-284Improper Access Control
T1204.002User Execution: Malicious 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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