USN-4747-1

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Source
https://ubuntu.com/security/notices/USN-4747-1
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4747-1.json
JSON Data
https://api.osv.dev/v1/vulns/USN-4747-1
Upstream
Related
Published
2021-02-24T13:58:42.115382Z
Modified
2025-10-13T04:35:21Z
Summary
screen vulnerability
Details

Felix Weinmann discovered that GNU Screen incorrectly handled certain character sequences. A remote attacker could use this issue to cause GNU Screen to crash, resulting in a denial of service, or possibly execute arbitrary code.

References

Affected packages

Ubuntu:16.04:LTS / screen

Package

Name
screen
Purl
pkg:deb/ubuntu/screen@4.3.1-2ubuntu0.1?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.3.1-2ubuntu0.1

Affected versions

4.*

4.3.1-2
4.3.1-2build1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "4.3.1-2ubuntu0.1",
            "binary_name": "screen"
        }
    ]
}

Database specific

cves_map

{
    "ecosystem": "Ubuntu:16.04:LTS",
    "cves": [
        {
            "id": "CVE-2021-26937",
            "severity": [
                {
                    "type": "CVSS_V3",
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
                },
                {
                    "type": "Ubuntu",
                    "score": "medium"
                }
            ]
        }
    ]
}

Ubuntu:18.04:LTS / screen

Package

Name
screen
Purl
pkg:deb/ubuntu/screen@4.6.2-1ubuntu1.1?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.6.2-1ubuntu1.1

Affected versions

4.*

4.6.1-1
4.6.2-1
4.6.2-1ubuntu1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "4.6.2-1ubuntu1.1",
            "binary_name": "screen"
        }
    ]
}

Database specific

cves_map

{
    "ecosystem": "Ubuntu:18.04:LTS",
    "cves": [
        {
            "id": "CVE-2021-26937",
            "severity": [
                {
                    "type": "CVSS_V3",
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
                },
                {
                    "type": "Ubuntu",
                    "score": "medium"
                }
            ]
        }
    ]
}

Ubuntu:20.04:LTS / screen

Package

Name
screen
Purl
pkg:deb/ubuntu/screen@4.8.0-1ubuntu0.1?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.8.0-1ubuntu0.1

Affected versions

4.*

4.6.2-3build1
4.7.0-1
4.8.0-1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "4.8.0-1ubuntu0.1",
            "binary_name": "screen"
        }
    ]
}

Database specific

cves_map

{
    "ecosystem": "Ubuntu:20.04:LTS",
    "cves": [
        {
            "id": "CVE-2021-26937",
            "severity": [
                {
                    "type": "CVSS_V3",
                    "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
                },
                {
                    "type": "Ubuntu",
                    "score": "medium"
                }
            ]
        }
    ]
}