CVE-2023-31470Network attack vector

Remote code execution via unchecked DNS encoding

Published Apr 28, 2023 · Updated Jan 31, 2025

Stack-based buffer overflow in pymumu SmartDNS 41 and earlier allows remote attackers to crash the service or execute arbitrary code. _dns_encode_domain in src/dns.c writes an encoded domain length byte beyond packet_buff because it fails to verify remaining packet capacity. An unauthenticated crafted DNS request reaches HTTPS record decoding; successful exploitation can terminate the server or corrupt control data.

CVSS severity9.8
Critical
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in pymumu SmartDNS 41 and earlier allows remote attackers to crash the service or execute arbitrary code. _dns_encode_domain in src/dns.c writes an encoded domain length byte beyond packet_buff because it fails to verify remaining packet capacity. An unauthenticated crafted DNS request reaches HTTPS record decoding; successful exploitation can terminate the server or corrupt control data.

The record

CVE
CVE-2023-31470
Published
Apr 28, 2023
Updated
Jan 31, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 28, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 31, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1190Exploit Public-Facing Application

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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