Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

Go to Calendar     Go to Press Room     Go to Newsletters subscription

Search

CVE-2019-15794

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
24/04/2020
Last modified:
26/05/2020

Description

Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.

Impact

Vector 3.x
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 6.70 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x
6.70
Severity 3.x
MEDIUM
Vector 2.0
AV:L/AC:L/Au:N/C:C/I:C/A:C CVSS v2.0 Severity and Metrics:

Base Score: 7.20 HIGH
Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): Complete
Integrity (I): Complete
Availability (A): Complete

Base Score 2.0
7.20
Severity 2.0
HIGH

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:linux:linux_kernel:5.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.3:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools