CVE-2024-27938

SMTP Smuggling in Postal

Severity Score

5.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Attend

*SSVC

Descriptions

Postal is an open source SMTP server. Postal versions less than 3.0.0 are vulnerable to SMTP Smuggling attacks which may allow incoming e-mails to be spoofed. This, in conjunction with a cooperative outgoing SMTP service, would allow for an incoming e-mail to be received by Postal addressed from a server that a user has 'authorised' to send mail on their behalf but were not the genuine author of the e-mail. Postal is not affected for sending outgoing e-mails as email is re-encoded with `<CR><LF>` line endings when transmitted over SMTP. This issue has been addressed and users should upgrade to Postal v3.0.0 or higher. Once upgraded, Postal will only accept End of DATA sequences which are explicitly `<CR><LF>.<CR><LF>`. If a non-compliant sequence is detected it will be logged to the SMTP server log. There are no workarounds for this issue.

Postal es un servidor SMTP de código abierto. Las versiones postales inferiores a 3.0.0 son vulnerables a ataques de contrabando SMTP que pueden permitir que los correos electrónicos entrantes sean falsificados. Esto, junto con un servicio SMTP saliente cooperativo, permitiría recibir un correo electrónico entrante por correo postal con dirección desde un servidor que un usuario ha "autorizado" a enviar correo en su nombre pero que no es el verdadero autor del correo electrónico. -correo. Postal no se ve afectado para el envío de correos electrónicos salientes, ya que el correo electrónico se vuelve a codificar con finales de línea `` cuando se transmite a través de SMTP. Este problema se solucionó y los usuarios deben actualizar a Postal v3.0.0 o superior. Una vez actualizado, Postal solo aceptará secuencias de fin de DATOS que sean explícitamente `.`. Si se detecta una secuencia no compatible, se registrará en el registro del servidor SMTP. No existen soluciones alternativas para este problema.

*Credits: N/A

CVSS Scores

GitHubv3.1 5.3

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:Attend

Exploitation

None

Automatable

Yes

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-02-28 CVE Reserved
2024-03-11 CVE Published
2024-03-12 EPSS Updated
2024-08-27 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-116: Improper Encoding or Escaping of Output

CAPEC

References (4)

URL	Tag	Source
https://github.com/postalserver/postal/commit/0140dc4	X_refsource_misc
https://github.com/postalserver/postal/security/advisories/GHSA-j42r-6c99-hqf2	X_refsource_confirm
https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide	X_refsource_misc
https://www.postfix.org/smtp-smuggling.html	X_refsource_misc

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Postalserver Search vendor "Postalserver"		Postal Search vendor "Postalserver" for product "Postal"				< 3.0.0 Search vendor "Postalserver" for product "Postal" and version " < 3.0.0"		en		Affected