CVE-2015-3644

Debian Security Advisory 3299-1

Severity Score

10.0

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Stunnel 5.00 through 5.13, when using the redirect option, does not redirect client connections to the expected server after the initial connection, which allows remote attackers to bypass authentication.

Stunnel 5.00 hasta 5.13, cuando utiliza la opción de redirección, no redirige las conexiones de clientes al servidor esperado después de la conexión inicial, lo que permite a atacantes remotos evadir la autenticación.

Johan Olofsson discovered an authentication bypass vulnerability in Stunnel, a program designed to work as an universal SSL tunnel for network daemons. When Stunnel in server mode is used with the redirect option and certificate-based authentication is enabled with "verify = 2" or higher, then only the initial connection is redirected to the hosts specified with "redirect". This allows a remote attacker to bypass authentication.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2015-05-04 CVE Reserved
2015-05-14 CVE Published
2024-08-06 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-284: Improper Access Control

CAPEC

References (4)

URL	Tag	Source
http://www.securityfocus.com/bid/74659	Vdb Entry
http://www.securitytracker.com/id/1032324	Vdb Entry

URL	Date	SRC

URL	Date	SRC
https://www.stunnel.org/CVE-2015-3644.html	2016-12-28

URL	Date	SRC
http://www.debian.org/security/2015/dsa-3299	2016-12-28

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.00 Search vendor "Stunnel" for product "Stunnel" and version "5.00"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.01 Search vendor "Stunnel" for product "Stunnel" and version "5.01"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.02 Search vendor "Stunnel" for product "Stunnel" and version "5.02"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.03 Search vendor "Stunnel" for product "Stunnel" and version "5.03"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.04 Search vendor "Stunnel" for product "Stunnel" and version "5.04"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.05 Search vendor "Stunnel" for product "Stunnel" and version "5.05"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.06 Search vendor "Stunnel" for product "Stunnel" and version "5.06"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.07 Search vendor "Stunnel" for product "Stunnel" and version "5.07"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.08 Search vendor "Stunnel" for product "Stunnel" and version "5.08"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.09 Search vendor "Stunnel" for product "Stunnel" and version "5.09"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.10 Search vendor "Stunnel" for product "Stunnel" and version "5.10"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.11 Search vendor "Stunnel" for product "Stunnel" and version "5.11"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.12 Search vendor "Stunnel" for product "Stunnel" and version "5.12"		-		Affected
Stunnel Search vendor "Stunnel"		Stunnel Search vendor "Stunnel" for product "Stunnel"				5.13 Search vendor "Stunnel" for product "Stunnel" and version "5.13"		-		Affected