UBUNTU-CVE-2021-34557

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Source

https://ubuntu.com/security/CVE-2021-34557

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-34557.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2021-34557

Upstream

CVE-2021-34557

Published

2021-06-10T16:15:00Z

Modified

2025-09-08T16:47:13Z

Severity

4.6 (Medium) CVSS_V3 - CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

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

References

Affected packages

Ubuntu:Pro:16.04:LTS / xscreensaver

Package

Name: xscreensaver
Purl: pkg:deb/ubuntu/xscreensaver@5.34-2ubuntu1?arch=source&distro=esm-apps/xenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.30-1ubuntu1

5.34-1ubuntu1

5.34-2ubuntu1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "5.34-2ubuntu1",
            "binary_name": "xscreensaver"
        },
        {
            "binary_version": "5.34-2ubuntu1",
            "binary_name": "xscreensaver-data"
        },
        {
            "binary_version": "5.34-2ubuntu1",
            "binary_name": "xscreensaver-data-extra"
        },
        {
            "binary_version": "5.34-2ubuntu1",
            "binary_name": "xscreensaver-gl"
        },
        {
            "binary_version": "5.34-2ubuntu1",
            "binary_name": "xscreensaver-gl-extra"
        },
        {
            "binary_version": "5.34-2ubuntu1",
            "binary_name": "xscreensaver-screensaver-bsod"
        },
        {
            "binary_version": "5.34-2ubuntu1",
            "binary_name": "xscreensaver-screensaver-webcollage"
        }
    ]
}

Ubuntu:Pro:18.04:LTS / xscreensaver

Package

Name: xscreensaver
Purl: pkg:deb/ubuntu/xscreensaver@5.36-1ubuntu1?arch=source&distro=esm-apps/bionic

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.36-1ubuntu1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "5.36-1ubuntu1",
            "binary_name": "xscreensaver"
        },
        {
            "binary_version": "5.36-1ubuntu1",
            "binary_name": "xscreensaver-data"
        },
        {
            "binary_version": "5.36-1ubuntu1",
            "binary_name": "xscreensaver-data-extra"
        },
        {
            "binary_version": "5.36-1ubuntu1",
            "binary_name": "xscreensaver-gl"
        },
        {
            "binary_version": "5.36-1ubuntu1",
            "binary_name": "xscreensaver-gl-extra"
        },
        {
            "binary_version": "5.36-1ubuntu1",
            "binary_name": "xscreensaver-screensaver-bsod"
        },
        {
            "binary_version": "5.36-1ubuntu1",
            "binary_name": "xscreensaver-screensaver-webcollage"
        }
    ]
}

Ubuntu:Pro:20.04:LTS / xscreensaver

Package

Name: xscreensaver
Purl: pkg:deb/ubuntu/xscreensaver@5.42+dfsg1-1ubuntu1?arch=source&distro=esm-apps/focal

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.42+dfsg1-1ubuntu1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "5.42+dfsg1-1ubuntu1",
            "binary_name": "xscreensaver"
        },
        {
            "binary_version": "5.42+dfsg1-1ubuntu1",
            "binary_name": "xscreensaver-data"
        },
        {
            "binary_version": "5.42+dfsg1-1ubuntu1",
            "binary_name": "xscreensaver-data-extra"
        },
        {
            "binary_version": "5.42+dfsg1-1ubuntu1",
            "binary_name": "xscreensaver-gl"
        },
        {
            "binary_version": "5.42+dfsg1-1ubuntu1",
            "binary_name": "xscreensaver-gl-extra"
        },
        {
            "binary_version": "5.42+dfsg1-1ubuntu1",
            "binary_name": "xscreensaver-screensaver-bsod"
        },
        {
            "binary_version": "5.42+dfsg1-1ubuntu1",
            "binary_name": "xscreensaver-screensaver-webcollage"
        }
    ]
}

Ubuntu:22.04:LTS / xscreensaver

Package

Name: xscreensaver
Purl: pkg:deb/ubuntu/xscreensaver@5.45+dfsg1-2ubuntu1?arch=source&distro=jammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.45+dfsg1-2ubuntu1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "5.45+dfsg1-2ubuntu1",
            "binary_name": "xscreensaver"
        },
        {
            "binary_version": "5.45+dfsg1-2ubuntu1",
            "binary_name": "xscreensaver-data"
        },
        {
            "binary_version": "5.45+dfsg1-2ubuntu1",
            "binary_name": "xscreensaver-data-extra"
        },
        {
            "binary_version": "5.45+dfsg1-2ubuntu1",
            "binary_name": "xscreensaver-gl"
        },
        {
            "binary_version": "5.45+dfsg1-2ubuntu1",
            "binary_name": "xscreensaver-gl-extra"
        },
        {
            "binary_version": "5.45+dfsg1-2ubuntu1",
            "binary_name": "xscreensaver-screensaver-bsod"
        },
        {
            "binary_version": "5.45+dfsg1-2ubuntu1",
            "binary_name": "xscreensaver-screensaver-webcollage"
        }
    ]
}