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Vulnerability details: VCID-1re6-vk5j-5yem
Vulnerability ID VCID-1re6-vk5j-5yem
Aliases CVE-2020-12397
Summary By encoding Unicode whitespace characters within the From email header, an attacker can spoof the sender email address that Thunderbird displays.
Status Published
Exploitability 0.5
Weighted Severity 9.0
Risk 4.5
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-172 Encoding Error
CWE-346 Origin Validation Error
System Score Found at
cvssv3 4.3 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-12397.json
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
epss 0.00184 https://api.first.org/data/v1/epss?cve=CVE-2020-12397
cvssv2 4.3 https://nvd.nist.gov/vuln/detail/CVE-2020-12397
cvssv3.1 4.3 https://nvd.nist.gov/vuln/detail/CVE-2020-12397
archlinux Critical https://security.archlinux.org/AVG-1155
generic_textual critical https://www.mozilla.org/en-US/security/advisories/mfsa2020-18
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-12397.json
https://api.first.org/data/v1/epss?cve=CVE-2020-12397
https://bugzilla.mozilla.org/show_bug.cgi?id=1617370
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://security.gentoo.org/glsa/202005-03
https://www.mozilla.org/security/advisories/mfsa2020-18/
1832565 https://bugzilla.redhat.com/show_bug.cgi?id=1832565
ASA-202005-7 https://security.archlinux.org/ASA-202005-7
AVG-1155 https://security.archlinux.org/AVG-1155
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:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
CVE-2020-12397 https://nvd.nist.gov/vuln/detail/CVE-2020-12397
mfsa2020-18 https://www.mozilla.org/en-US/security/advisories/mfsa2020-18
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-4373-1 https://usn.ubuntu.com/4373-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-12397.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: AV:N/AC:M/Au:N/C:N/I:P/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2020-12397
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:L/PR:N/UI:R/S:U/C:N/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2020-12397
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 0.40599
EPSS Score 0.00184
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:09:39.440501+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2020/mfsa2020-18.yml 37.0.0