CVE-2023-52354Network attack vector

Email sender impersonation via LF-terminated DATA lines

Published Jan 22, 2024 · Updated Jun 17, 2025

SMTP smuggling in chasquid before 1.13 allows remote attackers to impersonate email senders via LF-terminated DATA lines. The SMTP DATA reader delegates dot-terminated input to Go's net/textproto and net/mail handling, which accepts standalone LF and can misread the end-of-data marker. Unauthenticated network access to an SMTP listener is sufficient to create divergent message boundaries and impersonate the relay during server-to-server delivery.

CVSS severity7.5
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SMTP smuggling in chasquid before 1.13 allows remote attackers to impersonate email senders via LF-terminated DATA lines. The SMTP DATA reader delegates dot-terminated input to Go's net/textproto and net/mail handling, which accepts standalone LF and can misread the end-of-data marker. Unauthenticated network access to an SMTP listener is sufficient to create divergent message boundaries and impersonate the relay during server-to-server delivery.

The record

CVE
CVE-2023-52354
Published
Jan 22, 2024
Updated
Jun 17, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-444, T1656
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 22, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 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

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
T1656Impersonation

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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