4.6
MEDIUM
CVE-2021-34557
XScreenSaver Multiple Video Output Buffer Overflow Vulnerability
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.

INFO

Published Date :

June 10, 2021, 4:15 p.m.

Last Modified :

Nov. 7, 2023, 3:36 a.m.

Source :

[email protected]

Remotely Exploitable :

No

Impact Score :

3.6

Exploitability Score :

0.9
Affected Products

The following products are affected by CVE-2021-34557 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fedoraproject fedora
1 Xscreensaver_project xscreensaver
: Total Affected Vendor : 2 | Products : 2
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-34557.

URL Resource
http://www.openwall.com/lists/oss-security/2021/06/11/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/07/06/2 Exploit Mailing List Third Party Advisory
https://github.com/QubesOS/qubes-issues/issues/6595 Issue Tracking Third Party Advisory
https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt Exploit Third Party Advisory
https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
https://www.openwall.com/lists/oss-security/2021/06/05/1 Exploit Mailing List Third Party Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-34557 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-34557 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/ [No types assigned]
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/
  • Modified Analysis by [email protected]

    Sep. 21, 2021

    Action Type Old Value New Value
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/07/06/2 No Types Assigned http://www.openwall.com/lists/oss-security/2021/07/06/2 Exploit, Mailing List, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/ Mailing List, Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Aug. 19, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/TC4QB7TRS4GS7LDXQQ4PC6J3LVFJYISV/ [No Types Assigned]
  • CVE Modified by [email protected]

    Jul. 06, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/07/06/2 [No Types Assigned]
  • Initial Analysis by [email protected]

    Jun. 22, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:N/I:N/A:P)
    Added CVSS V3.1 NIST AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/06/11/1 No Types Assigned http://www.openwall.com/lists/oss-security/2021/06/11/1 Mailing List, Third Party Advisory
    Changed Reference Type https://github.com/QubesOS/qubes-issues/issues/6595 No Types Assigned https://github.com/QubesOS/qubes-issues/issues/6595 Issue Tracking, Third Party Advisory
    Changed Reference Type https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt No Types Assigned https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt Exploit, Third Party Advisory
    Changed Reference Type https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch No Types Assigned https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch Patch, Third Party Advisory
    Changed Reference Type https://www.openwall.com/lists/oss-security/2021/06/05/1 No Types Assigned https://www.openwall.com/lists/oss-security/2021/06/05/1 Exploit, Mailing List, Third Party Advisory
    Added CWE NIST CWE-120
    Added CPE Configuration OR *cpe:2.3:a:xscreensaver_project:xscreensaver:5.45:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Jun. 11, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/06/11/1 [No Types Assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-34557 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-34557 weaknesses.

CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-42: MIME Conversion MIME Conversion CAPEC-44: Overflow Binary Resource File Overflow Binary Resource File CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-92: Forced Integer Overflow Forced Integer Overflow CAPEC-100: Overflow Buffers Overflow Buffers
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.11 }} 0.01%

score

0.42514

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: