CVE-2023-31723Public exploit

Process crash via invalid macro-parameter read

Published May 17, 2023 · Updated Jan 22, 2025

A segmentation fault in Yasm 1.3.0.55.g101bc allows context-dependent attackers to crash an assembler process via a crafted assembly file. The expand_mmac_params function in modules/preprocs/nasm/nasm-pp.c performs an invalid read while expanding macro parameters, terminating the process. Processing the untrusted file requires user interaction, and Yasm's security policy treats assembly input as trusted developer code.

CVSS severity5.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A segmentation fault in Yasm 1.3.0.55.g101bc allows context-dependent attackers to crash an assembler process via a crafted assembly file. The expand_mmac_params function in modules/preprocs/nasm/nasm-pp.c performs an invalid read while expanding macro parameters, terminating the process. Processing the untrusted file requires user interaction, and Yasm's security policy treats assembly input as trusted developer code.

The record

CVE
CVE-2023-31723
Published
May 17, 2023
Updated
Jan 22, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 22, 2025Record 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

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS: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

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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