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TI-2024-18143 Aliases CVE-2024-27305GHSA-pr2m-px7j-xg65

SMTP smuggling in aiosmtpd

Priority LOW 30CWE-345Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-345.

Summary

aiosmtpd is a reimplementation of the Python stdlib smtpd.py based on asyncio. aiosmtpd is vulnerable to inbound SMTP smuggling. SMTP smuggling is a novel vulnerability based on not so novel interpretation differences of the SMTP protocol. By exploiting SMTP smuggling, an attacker may send smuggle/spoof e-mails with fake sender addresses, allowing advanced phishing attacks. This issue is also existed in other SMTP software like Postfix. With the right SMTP server constellation, an attacker can send spoofed e-mails to inbound/receiving aiosmtpd instances. This issue has been addressed in version 1.4.5. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00371 31st percentileScored 2026-11-07
Fix Fixed aiosmtpd (aio-libs): 1.4.5aiosmtpd (PyPI): 1.4.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
aio-libsaiosmtpdbefore 1.4.51.4.5Patch availableCNA
—aiosmtpd (PyPI)before 1.4.51.4.5Patch availableGHSA-pr2m-px7j-xg65
  • aiosmtpd Vendoraio-libs Affected before 1.4.5 Fixed in 1.4.5 Patch available CNA
  • aiosmtpd (PyPI) Vendor— Affected before 1.4.5 Fixed in 1.4.5 Patch available GHSA-pr2m-px7j-xg65

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:aio-libs:aiosmtpd:*:*:*:*:*:*:*:*before 1.4.5Vulnerableaio-libs
  • cpe:2.3:a:aio-libs:aiosmtpd:*:*:*:*:*:*:*:* Versions before 1.4.5 Vulnerable ·aio-libs

Remediation

  • Fix · CNA aiosmtpd (aio-libs) Fixed in 1.4.5
  • Fix · GHSA-pr2m-px7j-xg65 aiosmtpd (PyPI) Fixed in 1.4.5 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-27305
  2. 2026-10-03 Alias added: GHSA-pr2m-px7j-xg65

References

Patch 1

Advisory 2

Other 3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences