CVE-2020-35513

kernel: Nfsd failure to clear umask after processing an open or create

Severity Score

4.9

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

A flaw incorrect umask during file or directory modification in the Linux kernel NFS (network file system) functionality was found in the way user create and delete object using NFSv4.2 or newer if both simultaneously accessing the NFS by the other process that is not using new NFSv4.2. A user with access to the NFS could use this flaw to starve the resources causing denial of service.

Se encontró un fallo sin máscara incorrecto durante la modificación de archivos o directorios en la funcionalidad Linux kernel NFS (sistema de archivo de red) en la manera en que el usuario crea y elimina objetos usando NFSv4.2 o más reciente si ambos acceden simultáneamente al NFS por el otro proceso que no está usando el nuevo NFSv4.2. Un usuario con acceso al NFS podría usar este fallo para privar de recursos causando una denegación de servicio

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

High

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

Single

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-12-17 CVE Reserved
2021-01-25 CVE Published
2023-03-08 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-271: Privilege Dropping / Lowering Errors

CAPEC

References (3)

URL	Tag	Source
https://patchwork.kernel.org/project/linux-nfs/patch/20180403203916.GH20297%40fieldses.org	X_refsource_misc

URL	Date	SRC

URL	Date	SRC
https://bugzilla.redhat.com/show_bug.cgi?id=1911309	2021-02-02

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2020-35513	2021-02-02

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				4.2 Search vendor "Linux" for product "Linux Kernel" and version "4.2"		-		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