UBUNTU-CVE-2020-6820

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Source
https://ubuntu.com/security/CVE-2020-6820
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-6820.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2020-6820
Upstream
Downstream
Related
Published
2020-04-03T00:00:00Z
Modified
2025-09-08T16:45:58Z
Severity
  • 8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • 8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - high
Summary
[none]
Details

Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.

References

Affected packages

Ubuntu:16.04:LTS

firefox

Package

Name
firefox
Purl
pkg:deb/ubuntu/firefox@74.0.1+build1-0ubuntu0.16.04.1?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
74.0.1+build1-0ubuntu0.16.04.1

Affected versions

41.*

41.0.2+build2-0ubuntu1

42.*

42.0+build2-0ubuntu1

44.*

44.0+build3-0ubuntu2
44.0.1+build1-0ubuntu1
44.0.2+build1-0ubuntu1

45.*

45.0+build2-0ubuntu1
45.0.1+build1-0ubuntu1
45.0.2+build1-0ubuntu1

46.*

46.0+build5-0ubuntu0.16.04.2
46.0.1+build1-0ubuntu0.16.04.2

47.*

47.0+build3-0ubuntu0.16.04.1

48.*

48.0+build2-0ubuntu0.16.04.1

49.*

49.0+build4-0ubuntu0.16.04.1
49.0.2+build2-0ubuntu0.16.04.2

50.*

50.0+build2-0ubuntu0.16.04.2
50.0.2+build1-0ubuntu0.16.04.1
50.1.0+build2-0ubuntu0.16.04.1

51.*

51.0.1+build2-0ubuntu0.16.04.1
51.0.1+build2-0ubuntu0.16.04.2

52.*

52.0+build2-0ubuntu0.16.04.1
52.0.1+build2-0ubuntu0.16.04.1
52.0.2+build1-0ubuntu0.16.04.1

53.*

53.0+build6-0ubuntu0.16.04.1
53.0.2+build1-0ubuntu0.16.04.2
53.0.3+build1-0ubuntu0.16.04.2

54.*

54.0+build3-0ubuntu0.16.04.1

55.*

55.0.1+build2-0ubuntu0.16.04.2
55.0.2+build1-0ubuntu0.16.04.1

56.*

56.0+build6-0ubuntu0.16.04.1
56.0+build6-0ubuntu0.16.04.2

57.*

57.0+build4-0ubuntu0.16.04.5
57.0+build4-0ubuntu0.16.04.6
57.0.1+build2-0ubuntu0.16.04.1
57.0.3+build1-0ubuntu0.16.04.1
57.0.4+build1-0ubuntu0.16.04.1

58.*

58.0+build6-0ubuntu0.16.04.1
58.0.1+build1-0ubuntu0.16.04.1
58.0.2+build1-0ubuntu0.16.04.1

59.*

59.0+build5-0ubuntu0.16.04.1
59.0.1+build1-0ubuntu0.16.04.1
59.0.2+build1-0ubuntu0.16.04.1
59.0.2+build1-0ubuntu0.16.04.3

60.*

60.0+build2-0ubuntu0.16.04.1
60.0.1+build2-0ubuntu0.16.04.1
60.0.2+build1-0ubuntu0.16.04.1

61.*

61.0+build3-0ubuntu0.16.04.2
61.0.1+build1-0ubuntu0.16.04.1

62.*

62.0+build2-0ubuntu0.16.04.3
62.0+build2-0ubuntu0.16.04.4
62.0+build2-0ubuntu0.16.04.5
62.0.3+build1-0ubuntu0.16.04.2

63.*

63.0+build2-0ubuntu0.16.04.2
63.0.3+build1-0ubuntu0.16.04.1

64.*

64.0+build3-0ubuntu0.16.04.1

65.*

65.0+build2-0ubuntu0.16.04.1
65.0.1+build2-0ubuntu0.16.04.1

66.*

66.0+build3-0ubuntu0.16.04.2
66.0.1+build1-0ubuntu0.16.04.1
66.0.2+build1-0ubuntu0.16.04.1
66.0.3+build1-0ubuntu0.16.04.1
66.0.4+build3-0ubuntu0.16.04.1
66.0.5+build1-0ubuntu0.16.04.1

67.*

67.0+build2-0ubuntu0.16.04.1
67.0.1+build1-0ubuntu0.16.04.1
67.0.2+build2-0ubuntu0.16.04.1
67.0.3+build1-0ubuntu0.16.04.1
67.0.4+build1-0ubuntu0.16.04.1

68.*

68.0+build3-0ubuntu0.16.04.1
68.0.1+build1-0ubuntu0.16.04.1
68.0.2+build1-0ubuntu0.16.04.1

69.*

69.0+build2-0ubuntu0.16.04.4
69.0.1+build1-0ubuntu0.16.04.1
69.0.2+build1-0ubuntu0.16.04.1

70.*

70.0+build2-0ubuntu0.16.04.1
70.0.1+build1-0ubuntu0.16.04.1

71.*

71.0+build5-0ubuntu0.16.04.1

72.*

72.0.1+build1-0ubuntu0.16.04.1
72.0.2+build1-0ubuntu0.16.04.1

73.*

73.0.1+build1-0ubuntu0.16.04.1

74.*

74.0+build3-0ubuntu0.16.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "74.0.1+build1-0ubuntu0.16.04.1",
            "binary_name": "firefox"
        },
        {
            "binary_version": "74.0.1+build1-0ubuntu0.16.04.1",
            "binary_name": "firefox-dev"
        },
        {
            "binary_version": "74.0.1+build1-0ubuntu0.16.04.1",
            "binary_name": "firefox-geckodriver"
        },
        {
            "binary_version": "74.0.1+build1-0ubuntu0.16.04.1",
            "binary_name": "firefox-mozsymbols"
        }
    ]
}

thunderbird

Package

Name
thunderbird
Purl
pkg:deb/ubuntu/thunderbird@1:68.7.0+build1-0ubuntu0.16.04.2?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1:68.7.0+build1-0ubuntu0.16.04.2

Affected versions

1:38.*

1:38.3.0+build1-0ubuntu2
1:38.5.1+build2-0ubuntu1
1:38.6.0+build1-0ubuntu1
1:38.7.2+build1-0ubuntu0.16.04.1
1:38.8.0+build1-0ubuntu0.16.04.1

1:45.*

1:45.2.0+build1-0ubuntu0.16.04.1
1:45.3.0+build1-0ubuntu0.16.04.2
1:45.4.0+build1-0ubuntu0.16.04.1
1:45.5.1+build1-0ubuntu0.16.04.1
1:45.7.0+build1-0ubuntu0.16.04.1
1:45.8.0+build1-0ubuntu0.16.04.1

1:52.*

1:52.1.1+build1-0ubuntu0.16.04.1
1:52.2.1+build1-0ubuntu0.16.04.1
1:52.3.0+build1-0ubuntu0.16.04.1
1:52.4.0+build1-0ubuntu0.16.04.2
1:52.5.0+build1-0ubuntu0.16.04.1
1:52.6.0+build1-0ubuntu0.16.04.1
1:52.7.0+build1-0ubuntu0.16.04.1
1:52.8.0+build1-0ubuntu0.16.04.1
1:52.9.1+build3-0ubuntu0.16.04.1

1:60.*

1:60.2.1+build1-0ubuntu0.16.04.4
1:60.4.0+build2-0ubuntu0.16.04.1
1:60.5.1+build2-0ubuntu0.16.04.1
1:60.6.1+build2-0ubuntu0.16.04.1
1:60.7.0+build1-0ubuntu0.16.04.1
1:60.7.1+build1-0ubuntu0.16.04.1
1:60.7.2+build2-0ubuntu0.16.04.1
1:60.8.0+build1-0ubuntu0.16.04.2
1:60.9.0+build1-0ubuntu0.16.04.2
1:60.9.1+build1-0ubuntu0.16.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.16.04.2",
            "binary_name": "thunderbird"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.16.04.2",
            "binary_name": "thunderbird-dev"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.16.04.2",
            "binary_name": "thunderbird-gnome-support"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.16.04.2",
            "binary_name": "thunderbird-mozsymbols"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.16.04.2",
            "binary_name": "xul-ext-calendar-timezones"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.16.04.2",
            "binary_name": "xul-ext-gdata-provider"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.16.04.2",
            "binary_name": "xul-ext-lightning"
        }
    ]
}

Ubuntu:18.04:LTS

firefox

Package

Name
firefox
Purl
pkg:deb/ubuntu/firefox@74.0.1+build1-0ubuntu0.18.04.1?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
74.0.1+build1-0ubuntu0.18.04.1

Affected versions

56.*

56.0+build6-0ubuntu1

57.*

57.0.1+build2-0ubuntu1

59.*

59.0.1+build1-0ubuntu1
59.0.2+build1-0ubuntu1

60.*

60.0+build2-0ubuntu1
60.0.1+build2-0ubuntu0.18.04.1
60.0.2+build1-0ubuntu0.18.04.1

61.*

61.0+build3-0ubuntu0.18.04.1
61.0.1+build1-0ubuntu0.18.04.1

62.*

62.0+build2-0ubuntu0.18.04.3
62.0+build2-0ubuntu0.18.04.4
62.0+build2-0ubuntu0.18.04.5
62.0.3+build1-0ubuntu0.18.04.1

63.*

63.0+build2-0ubuntu0.18.04.2
63.0.3+build1-0ubuntu0.18.04.1

64.*

64.0+build3-0ubuntu0.18.04.1

65.*

65.0+build2-0ubuntu0.18.04.1
65.0.1+build2-0ubuntu0.18.04.1

66.*

66.0+build3-0ubuntu0.18.04.1
66.0.1+build1-0ubuntu0.18.04.1
66.0.2+build1-0ubuntu0.18.04.1
66.0.3+build1-0ubuntu0.18.04.1
66.0.4+build3-0ubuntu0.18.04.1
66.0.5+build1-0ubuntu0.18.04.1

67.*

67.0+build2-0ubuntu0.18.04.1
67.0.1+build1-0ubuntu0.18.04.1
67.0.2+build2-0ubuntu0.18.04.1
67.0.3+build1-0ubuntu0.18.04.1
67.0.4+build1-0ubuntu0.18.04.1

68.*

68.0+build3-0ubuntu0.18.04.1
68.0.1+build1-0ubuntu0.18.04.1
68.0.2+build1-0ubuntu0.18.04.1

69.*

69.0+build2-0ubuntu0.18.04.1
69.0.1+build1-0ubuntu0.18.04.1
69.0.2+build1-0ubuntu0.18.04.1

70.*

70.0+build2-0ubuntu0.18.04.1
70.0.1+build1-0ubuntu0.18.04.1

71.*

71.0+build5-0ubuntu0.18.04.1

72.*

72.0.1+build1-0ubuntu0.18.04.1
72.0.2+build1-0ubuntu0.18.04.1

73.*

73.0+build3-0ubuntu0.18.04.1
73.0.1+build1-0ubuntu0.18.04.1

74.*

74.0+build3-0ubuntu0.18.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "74.0.1+build1-0ubuntu0.18.04.1",
            "binary_name": "firefox"
        },
        {
            "binary_version": "74.0.1+build1-0ubuntu0.18.04.1",
            "binary_name": "firefox-dev"
        },
        {
            "binary_version": "74.0.1+build1-0ubuntu0.18.04.1",
            "binary_name": "firefox-geckodriver"
        },
        {
            "binary_version": "74.0.1+build1-0ubuntu0.18.04.1",
            "binary_name": "firefox-mozsymbols"
        }
    ]
}

thunderbird

Package

Name
thunderbird
Purl
pkg:deb/ubuntu/thunderbird@1:68.7.0+build1-0ubuntu0.18.04.1?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1:68.7.0+build1-0ubuntu0.18.04.1

Affected versions

1:52.*

1:52.4.0+build1-0ubuntu2
1:52.6.0+build1-0ubuntu1
1:52.7.0+build1-0ubuntu1
1:52.8.0+build1-0ubuntu0.18.04.1
1:52.9.1+build3-0ubuntu0.18.04.1

1:60.*

1:60.2.1+build1-0ubuntu0.18.04.2
1:60.4.0+build2-0ubuntu0.18.04.1
1:60.5.1+build2-0ubuntu0.18.04.1
1:60.6.1+build2-0ubuntu0.18.04.1
1:60.7.0+build1-0ubuntu0.18.04.1
1:60.7.1+build1-0ubuntu0.18.04.1
1:60.7.2+build2-0ubuntu0.18.04.1
1:60.8.0+build1-0ubuntu0.18.04.1
1:60.9.0+build1-0ubuntu0.18.04.1

1:68.*

1:68.2.1+build1-0ubuntu0.18.04.1
1:68.2.2+build1-0ubuntu0.18.04.1
1:68.4.1+build1-0ubuntu0.18.04.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.18.04.1",
            "binary_name": "thunderbird"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.18.04.1",
            "binary_name": "thunderbird-dev"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.18.04.1",
            "binary_name": "thunderbird-gnome-support"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.18.04.1",
            "binary_name": "thunderbird-mozsymbols"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.18.04.1",
            "binary_name": "xul-ext-calendar-timezones"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.18.04.1",
            "binary_name": "xul-ext-gdata-provider"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu0.18.04.1",
            "binary_name": "xul-ext-lightning"
        }
    ]
}

Ubuntu:20.04:LTS

firefox

Package

Name
firefox
Purl
pkg:deb/ubuntu/firefox@75.0+build3-0ubuntu1?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
75.0+build3-0ubuntu1

Affected versions

69.*

69.0.3+build1-0ubuntu1

70.*

70.0+build2-0ubuntu1
70.0+build2-0ubuntu2
70.0.1+build1-0ubuntu2

71.*

71.0+build2-0ubuntu2
71.0+build5-0ubuntu1

72.*

72.0.1+build1-0ubuntu1
72.0.2+build1-0ubuntu1

73.*

73.0+build1-0ubuntu1
73.0+build2-0ubuntu1
73.0+build3-0ubuntu1
73.0.1+build1-0ubuntu1

74.*

74.0+build1-0ubuntu1
74.0+build2-0ubuntu1
74.0+build2-0ubuntu2
74.0+build3-0ubuntu1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "75.0+build3-0ubuntu1",
            "binary_name": "firefox"
        },
        {
            "binary_version": "75.0+build3-0ubuntu1",
            "binary_name": "firefox-dev"
        },
        {
            "binary_version": "75.0+build3-0ubuntu1",
            "binary_name": "firefox-geckodriver"
        },
        {
            "binary_version": "75.0+build3-0ubuntu1",
            "binary_name": "firefox-mozsymbols"
        }
    ]
}

thunderbird

Package

Name
thunderbird
Purl
pkg:deb/ubuntu/thunderbird@1:68.7.0+build1-0ubuntu1?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1:68.7.0+build1-0ubuntu1

Affected versions

1:68.*

1:68.1.2+build1-0ubuntu1
1:68.1.2+build1-0ubuntu2
1:68.2.1+build1-0ubuntu1
1:68.2.2+build1-0ubuntu1
1:68.3.0+build2-0ubuntu1
1:68.3.1+build1-0ubuntu2
1:68.4.1+build1-0ubuntu1
1:68.4.2+build2-0ubuntu1
1:68.5.0+build1-0ubuntu1
1:68.6.0+build2-0ubuntu1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_version": "1:68.7.0+build1-0ubuntu1",
            "binary_name": "thunderbird"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu1",
            "binary_name": "thunderbird-dev"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu1",
            "binary_name": "thunderbird-gnome-support"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu1",
            "binary_name": "thunderbird-mozsymbols"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu1",
            "binary_name": "xul-ext-calendar-timezones"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu1",
            "binary_name": "xul-ext-gdata-provider"
        },
        {
            "binary_version": "1:68.7.0+build1-0ubuntu1",
            "binary_name": "xul-ext-lightning"
        }
    ]
}