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Vulnerability details: VCID-3cvj-hax2-aaam
Vulnerability ID VCID-3cvj-hax2-aaam
Aliases CVE-2020-12387
Summary A race condition when running shutdown code for Web Worker led to a use-after-free vulnerability. This resulted in a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.8, Firefox < 76, and Thunderbird < 68.8.0.
Status Published
Exploitability 0.5
Weighted Severity 9.0
Risk 4.5
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-416 Use After Free
System Score Found at
generic_textual Medium http://people.canonical.com/~ubuntu-security/cve/2020/CVE-2020-12387.html
rhas Critical https://access.redhat.com/errata/RHSA-2020:2031
rhas Critical https://access.redhat.com/errata/RHSA-2020:2032
rhas Critical https://access.redhat.com/errata/RHSA-2020:2033
rhas Critical https://access.redhat.com/errata/RHSA-2020:2036
rhas Critical https://access.redhat.com/errata/RHSA-2020:2037
rhas Critical https://access.redhat.com/errata/RHSA-2020:2046
rhas Critical https://access.redhat.com/errata/RHSA-2020:2047
rhas Critical https://access.redhat.com/errata/RHSA-2020:2048
rhas Critical https://access.redhat.com/errata/RHSA-2020:2049
rhas Critical https://access.redhat.com/errata/RHSA-2020:2050
cvssv3 8.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-12387.json
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
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epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
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epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
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epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
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epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
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epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.00998 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01003 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01152 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01152 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01152 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.01152 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
epss 0.0149 https://api.first.org/data/v1/epss?cve=CVE-2020-12387
rhbs urgent https://bugzilla.redhat.com/show_bug.cgi?id=1831761
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12387
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12392
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12395
generic_textual Low https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12397
generic_textual Medium https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-6831
cvssv3.1 8.8 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv2 6.8 https://nvd.nist.gov/vuln/detail/CVE-2020-12387
cvssv3 8.1 https://nvd.nist.gov/vuln/detail/CVE-2020-12387
cvssv3.1 8.1 https://nvd.nist.gov/vuln/detail/CVE-2020-12387
archlinux Critical https://security.archlinux.org/AVG-1148
archlinux Critical https://security.archlinux.org/AVG-1155
generic_textual Medium https://ubuntu.com/security/notices/USN-4353-1
generic_textual Medium https://ubuntu.com/security/notices/USN-4373-1
generic_textual Medium https://usn.ubuntu.com/usn/usn-4353-1
generic_textual Medium https://usn.ubuntu.com/usn/usn-4373-1
generic_textual critical https://www.mozilla.org/en-US/security/advisories/mfsa2020-16
generic_textual Medium https://www.mozilla.org/en-US/security/advisories/mfsa2020-16/#CVE-2020-12387
generic_textual critical https://www.mozilla.org/en-US/security/advisories/mfsa2020-17
generic_textual Medium https://www.mozilla.org/en-US/security/advisories/mfsa2020-17/#CVE-2020-12387
generic_textual critical https://www.mozilla.org/en-US/security/advisories/mfsa2020-18
generic_textual Medium https://www.mozilla.org/en-US/security/advisories/mfsa2020-18/#CVE-2020-12387
Reference id Reference type URL
http://people.canonical.com/~ubuntu-security/cve/2020/CVE-2020-12387.html
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-12387.json
https://api.first.org/data/v1/epss?cve=CVE-2020-12387
https://bugzilla.mozilla.org/show_bug.cgi?id=1545345
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12387
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12392
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12395
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12397
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-6831
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://security.gentoo.org/glsa/202005-03
https://security.gentoo.org/glsa/202005-04
https://ubuntu.com/security/notices/USN-4353-1
https://ubuntu.com/security/notices/USN-4373-1
https://usn.ubuntu.com/4373-1/
https://usn.ubuntu.com/usn/usn-4353-1
https://usn.ubuntu.com/usn/usn-4373-1
https://www.mozilla.org/en-US/security/advisories/mfsa2020-16/#CVE-2020-12387
https://www.mozilla.org/en-US/security/advisories/mfsa2020-17/#CVE-2020-12387
https://www.mozilla.org/en-US/security/advisories/mfsa2020-18/#CVE-2020-12387
https://www.mozilla.org/security/advisories/mfsa2020-16/
https://www.mozilla.org/security/advisories/mfsa2020-17/
https://www.mozilla.org/security/advisories/mfsa2020-18/
1831761 https://bugzilla.redhat.com/show_bug.cgi?id=1831761
ASA-202005-3 https://security.archlinux.org/ASA-202005-3
ASA-202005-7 https://security.archlinux.org/ASA-202005-7
AVG-1148 https://security.archlinux.org/AVG-1148
AVG-1155 https://security.archlinux.org/AVG-1155
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
CVE-2020-12387 https://nvd.nist.gov/vuln/detail/CVE-2020-12387
mfsa2020-16 https://www.mozilla.org/en-US/security/advisories/mfsa2020-16
mfsa2020-17 https://www.mozilla.org/en-US/security/advisories/mfsa2020-17
mfsa2020-18 https://www.mozilla.org/en-US/security/advisories/mfsa2020-18
RHSA-2020:2031 https://access.redhat.com/errata/RHSA-2020:2031
RHSA-2020:2032 https://access.redhat.com/errata/RHSA-2020:2032
RHSA-2020:2033 https://access.redhat.com/errata/RHSA-2020:2033
RHSA-2020:2036 https://access.redhat.com/errata/RHSA-2020:2036
RHSA-2020:2037 https://access.redhat.com/errata/RHSA-2020:2037
RHSA-2020:2046 https://access.redhat.com/errata/RHSA-2020:2046
RHSA-2020:2047 https://access.redhat.com/errata/RHSA-2020:2047
RHSA-2020:2048 https://access.redhat.com/errata/RHSA-2020:2048
RHSA-2020:2049 https://access.redhat.com/errata/RHSA-2020:2049
RHSA-2020:2050 https://access.redhat.com/errata/RHSA-2020:2050
USN-4353-1 https://usn.ubuntu.com/4353-1/
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-12387.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2020-12387
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2020-12387
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2020-12387
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.74946
EPSS Score 0.00998
Published At March 28, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
There are no relevant records.