CVE-2020-1045

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

11/09/2020

Last modified:

23/02/2026

Description

A security feature bypass vulnerability exists in the way Microsoft ASP.NET Core parses encoded cookie names.<br /> The ASP.NET Core cookie parser decodes entire cookie strings which could allow a malicious attacker to set a second cookie with the name being percent encoded.<br /> The security update addresses the vulnerability by fixing the way the ASP.NET Core cookie parser handles encoded names.

Impact

Vector 3.x

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

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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

Base Score 3.x

7.50

Severity 3.x

HIGH

Vector 2.0

AV:N/AC:L/Au:N/C:N/I:P/A:N CVSS v2.0 Severity and Metrics:

Base Score: 5.00 MEDIUM
Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N

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

Base Score 2.0

5.00

Severity 2.0

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:microsoft:asp.net_core::::::::	2.1 (including)	2.1.21 (including)
cpe:2.3:a:microsoft:asp.net_core::::::::	3.1 (including)	3.1.8 (excluding)
cpe:2.3:o:fedoraproject:fedora:32:::::::*
cpe:2.3:o:fedoraproject:fedora:33:::::::*
cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*
cpe:2.3:o:redhat:enterprise_linux_aus:8.2:::::::*
cpe:2.3:o:redhat:enterprise_linux_aus:8.4:::::::*
cpe:2.3:o:redhat:enterprise_linux_aus:8.6:::::::*
cpe:2.3:o:redhat:enterprise_linux_eus:8.2:::::::*
cpe:2.3:o:redhat:enterprise_linux_eus:8.4:::::::*
cpe:2.3:o:redhat:enterprise_linux_eus:8.6:::::::*
cpe:2.3:o:redhat:enterprise_linux_tus:8.2:::::::*
cpe:2.3:o:redhat:enterprise_linux_tus:8.4:::::::*
cpe:2.3:o:redhat:enterprise_linux_tus:8.6:::::::*

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

CPE	From	Up to
cpe:2.3:a:microsoft:asp.net_core::::::::	2.1 (including)	2.1.21 (including)
cpe:2.3:a:microsoft:asp.net_core::::::::	3.1 (including)	3.1.8 (excluding)
cpe:2.3:o:fedoraproject:fedora:32:::::::*
cpe:2.3:o:fedoraproject:fedora:33:::::::*
cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*
cpe:2.3:o:redhat:enterprise_linux_aus:8.2:::::::*
cpe:2.3:o:redhat:enterprise_linux_aus:8.4:::::::*
cpe:2.3:o:redhat:enterprise_linux_aus:8.6:::::::*
cpe:2.3:o:redhat:enterprise_linux_eus:8.2:::::::*
cpe:2.3:o:redhat:enterprise_linux_eus:8.4:::::::*
cpe:2.3:o:redhat:enterprise_linux_eus:8.6:::::::*
cpe:2.3:o:redhat:enterprise_linux_tus:8.2:::::::*
cpe:2.3:o:redhat:enterprise_linux_tus:8.4:::::::*
cpe:2.3:o:redhat:enterprise_linux_tus:8.6:::::::*

CVE-2020-1045

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools