CVE-2021-20208

Ubuntu Security Notice USN-5459-1

Severity Score

6.1

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

A flaw was found in cifs-utils in versions before 6.13. A user when mounting a krb5 CIFS file system from within a container can use Kerberos credentials of the host. The highest threat from this vulnerability is to data confidentiality and integrity.

Se encontró un fallo en cifs-utils en versiones anteriores a la 6.13. Cuando un usuario monta un sistema de archivos CIFS krb5 desde un contenedor, puede usar las credenciales de Kerberos del host. La mayor amenaza de esta vulnerabilidad es la confidencialidad e integridad de los datos

Aurélien Aptel discovered that cifs-utils invoked a shell when requesting a password. In certain environments, a local attacker could possibly use this issue to escalate privileges. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. It was discovered that cifs-utils incorrectly used host credentials when mounting a krb5 CIFS file system from within a container. An attacker inside a container could possibly use this issue to obtain access to sensitive information. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.

*Credits: N/A

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

Single

Confidentiality

Partial

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-12-17 CVE Reserved
2021-04-19 CVE Published
2024-08-03 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-266: Incorrect Privilege Assignment
CWE-269: Improper Privilege Management

CAPEC

References (5)

URL	Tag	Source
https://bugzilla.redhat.com/show_bug.cgi?id=1921116	Issue Tracking

URL	Date	SRC

URL	Date	SRC
https://bugzilla.samba.org/show_bug.cgi?id=14651	2023-11-07

URL	Date	SRC
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2W4HSDIWXXNQBUW5ZS37RQMLJ7THK5AS	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/66WJ3SVBHCSNQZAWSGLB6FBOCFU45FFG	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z4BZSJXROEFHYATAAHHRR6P3HUSMPQB3	2023-11-07

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Samba Search vendor "Samba"		Cifs-utils Search vendor "Samba" for product "Cifs-utils"				>= 4.0 < 6.13 Search vendor "Samba" for product "Cifs-utils" and version " >= 4.0 < 6.13"		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				7.0 Search vendor "Redhat" for product "Enterprise Linux" and version "7.0"		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				8.0 Search vendor "Redhat" for product "Enterprise Linux" and version "8.0"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				33 Search vendor "Fedoraproject" for product "Fedora" and version "33"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				34 Search vendor "Fedoraproject" for product "Fedora" and version "34"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				35 Search vendor "Fedoraproject" for product "Fedora" and version "35"		-		Affected