CVE-2021-34557

Severity CVSS v4.0:

Pending analysis

Type:

CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Publication date:

10/06/2021

Last modified:

07/11/2023

Description

XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs. A buffer overflow in update_screen_layout() allows an attacker to bypass the standard screen lock authentication mechanism by crashing XScreenSaver. The attacker must physically disconnect many video outputs.

Impact

Vector 3.x

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

Base Score: 4.60 MEDIUM
Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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

Base Score 3.x

4.60

Severity 3.x

MEDIUM

Vector 2.0

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

Base Score: 2.10 LOW
Vector: AV:L/AC:L/Au:N/C:N/I:N/A:P

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