UBUNTU-CVE-2020-28049

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Source
https://ubuntu.com/security/CVE-2020-28049
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-28049.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2020-28049
Upstream
Published
2020-11-04T19:15:00Z
Modified
2025-09-08T16:46:28Z
Severity
  • 6.3 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
  • 6.3 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
  • Ubuntu - low
Summary
[none]
Details

An issue was discovered in SDDM before 0.19.0. It incorrectly starts the X server in a way that - for a short time period - allows local unprivileged users to create a connection to the X server without providing proper authentication. A local attacker can thus access X server display contents and, for example, intercept keystrokes or access the clipboard. This is caused by a race condition during Xauthority file creation.

References

Affected packages

Ubuntu:Pro:16.04:LTS / sddm

Package

Name
sddm
Purl
pkg:deb/ubuntu/sddm@0.13.0-1ubuntu5?arch=source&distro=esm-apps/xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*

0.11.0-0ubuntu11
0.11.0-0ubuntu12
0.13.0-1ubuntu1
0.13.0-1ubuntu3
0.13.0-1ubuntu4
0.13.0-1ubuntu5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "sddm",
            "binary_version": "0.13.0-1ubuntu5"
        },
        {
            "binary_name": "sddm-theme-circles",
            "binary_version": "0.13.0-1ubuntu5"
        },
        {
            "binary_name": "sddm-theme-elarun",
            "binary_version": "0.13.0-1ubuntu5"
        },
        {
            "binary_name": "sddm-theme-maldives",
            "binary_version": "0.13.0-1ubuntu5"
        },
        {
            "binary_name": "sddm-theme-maui",
            "binary_version": "0.13.0-1ubuntu5"
        }
    ]
}

Ubuntu:Pro:18.04:LTS / sddm

Package

Name
sddm
Purl
pkg:deb/ubuntu/sddm@0.17.0-1ubuntu7?arch=source&distro=esm-apps/bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*

0.14.0-4ubuntu1
0.14.0-4ubuntu2
0.17.0-1ubuntu1
0.17.0-1ubuntu2
0.17.0-1ubuntu3
0.17.0-1ubuntu4
0.17.0-1ubuntu5
0.17.0-1ubuntu6
0.17.0-1ubuntu7

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "sddm",
            "binary_version": "0.17.0-1ubuntu7"
        },
        {
            "binary_name": "sddm-theme-debian-elarun",
            "binary_version": "0.17.0-1ubuntu7"
        },
        {
            "binary_name": "sddm-theme-debian-maui",
            "binary_version": "0.17.0-1ubuntu7"
        },
        {
            "binary_name": "sddm-theme-elarun",
            "binary_version": "0.17.0-1ubuntu7"
        },
        {
            "binary_name": "sddm-theme-maldives",
            "binary_version": "0.17.0-1ubuntu7"
        },
        {
            "binary_name": "sddm-theme-maui",
            "binary_version": "0.17.0-1ubuntu7"
        },
        {
            "binary_name": "sddm-theme-maya",
            "binary_version": "0.17.0-1ubuntu7"
        }
    ]
}

Ubuntu:Pro:20.04:LTS / sddm

Package

Name
sddm
Purl
pkg:deb/ubuntu/sddm@0.18.1-1ubuntu2?arch=source&distro=esm-apps/focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*

0.18.0-1ubuntu2
0.18.1-1ubuntu1
0.18.1-1ubuntu2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "sddm",
            "binary_version": "0.18.1-1ubuntu2"
        },
        {
            "binary_name": "sddm-theme-debian-elarun",
            "binary_version": "0.18.1-1ubuntu2"
        },
        {
            "binary_name": "sddm-theme-debian-maui",
            "binary_version": "0.18.1-1ubuntu2"
        },
        {
            "binary_name": "sddm-theme-elarun",
            "binary_version": "0.18.1-1ubuntu2"
        },
        {
            "binary_name": "sddm-theme-maldives",
            "binary_version": "0.18.1-1ubuntu2"
        },
        {
            "binary_name": "sddm-theme-maui",
            "binary_version": "0.18.1-1ubuntu2"
        },
        {
            "binary_name": "sddm-theme-maya",
            "binary_version": "0.18.1-1ubuntu2"
        }
    ]
}