IM
IronMonkey Threat Research

CVE-2018-20482 MEDIUM

Published: 2018-12-26 | Last Modified: 2026-06-17 | Status: Modified

Description

GNU Tar through 1.30, when --sparse is used, mishandles file shrinkage during read access, which allows local users to cause a denial of service (infinite read loop in sparse_dump_region in sparse.c) by modifying a file that is supposed to be archived by a different user's process (e.g., a system backup running as root).

Additional Descriptions (1)

GNU Tar, hasta la versión 1.30, cuando se emplea --sparse, gestiona de manera incorrecta el encogimiento de archivos durante el acceso de lectura, lo que permite que usuarios locales provoquen una denegación de servicio (bucle infinito de lectura en sparse_dump_region en sparse.c) modificando un archivo que debería ser archivado por el proceso de un usuario diferente (por ejemplo, un backup del sistema que se ejecuta como root).

CVSS Metrics

Base Score: 4.7 (MEDIUM)

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack VectorLOCAL
Attack ComplexityHIGH
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactNONE
Integrity ImpactNONE
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.0

Impact Score: 3.6

Base Score: 1.9 (LOW)

AV:L/AC:M/Au:N/C:N/I:N/A:P

Access VectorLOCAL
Access ComplexityMEDIUM
AuthenticationNONE
Confidentiality ImpactNONE
Integrity ImpactNONE
Availability ImpactPARTIAL

Source: [email protected]

Type: Primary

Exploitability Score: 3.4

Impact Score: 2.9

Weaknesses

Source Type Description
[email protected] Primary
en CWE-835

Affected Products

Vendor Product Version Update Type
gnu tar * <built-in method update of dict object at 0x7fd340f0cb80> Application
debian debian_linux 8.0 <built-in method update of dict object at 0x7fd340f0fbc0> Operating System
debian debian_linux 9.0 <built-in method update of dict object at 0x7fd36a701480> Operating System
opensuse leap 15.0 <built-in method update of dict object at 0x7fd3412ba040> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:a:gnu:tar:*:*:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
Yes cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*

References