GHSA-pr2m-px7j-xg65 — medium GitHub Advisory (CVE-2024-27305) in pip/aiosmtpd

Description

Summary

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 also existed in other SMTP software like Postfix (https://www.postfix.org/smtp-smuggling.html).

Details

Detailed information on SMTP smuggling can be found in the full blog post (https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/) or on the Postfix homepage (https://www.postfix.org/smtp-smuggling.html). (and soon on the official website https://smtpsmuggling.com/)

Impact

With the right SMTP server constellation, an attacker can send spoofed e-mails to inbound/receiving aiosmtpd instances.

Basic information

Type: reviewed
Severity: medium
Advisory on GitHub: Open advisory ↗
Repository advisory: Open repository advisory ↗
Source code: Browse source ↗
Published (advisory): 2024-03-13 15:33:14 UTC
Updated: 2025-01-22 18:45:42 UTC
GitHub reviewed: 2024-03-13 15:33:14 UTC
NVD published: 2024-03-12

Score	Percentile
0.73%	72.62%

CVSS Scores

Base score	Version	Severity	Vector
5.3	3.1	—	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.

Identifiers

Type	Value
GHSA	GHSA-pr2m-px7j-xg65 ↗
CVE	CVE-2024-27305 ↗

CWEs

CWE id	Name
CWE-345	Insufficient Verification of Data Authenticity

Credits

The-Login (reporter)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem	Package	Vulnerable range	First patched	Vulnerable functions
pip	aiosmtpd	< 1.4.5	1.4.5	—

aiosmtpd vulnerable to SMTP smuggling