synced 9 MIN AGO
01 Record

CVE-2021-43528

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a

UnratedPUBLISHEDCNA: mozilla
CNA base scoreUnratedNo CNA CVSS vector

02 Description

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a

03 Exploitation and scoring

Exploitation
Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
SSVC decision
Not assessed by CISA
EPSS probability
1.30% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 70.1% of scored records. A rank, not a probability.
NVD base score
6.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2021-12-08 21:21Z4 YR AGO
Last updated
2024-08-04 03:55Z2 YR AGO
Reserved
2021-11-08
Assigning CNA
mozilla
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-269Improper Privilege ManagementClass
  • CWE-281Improper Preservation of PermissionsBase
Data version
5.1
Document digest
f56875bdf38a99983089c60a6d7b620bb10f39f3ae2e8c72b6b45f4b95405ac1

05 Affected products

VendorProductVersionsPlatforms
MozillaThunderbird< 91.4.0—

06 References

07 Fixed in

AlmaLinux 8

  • thunderbird
    Fixed

    A version is affected if any line below covers it.

    • Affected before 91.4.0-2.el8_5.alma
    • Affected before 91.4.0-2.el8_5.alma.plus

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Arch Linux

  • thunderbird
    Fixed in 91.4.0-1

Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.

CloudLinux 8

  • thunderbird
    Fixed

    A version is affected if any line below covers it.

    • Affected before 91.4.0-2.el8_5.alma
    • Affected before 91.4.0-2.el8_5.alma.plus

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • thunderbird
    Fixed in 1:91.4.0-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • thunderbird
    Fixed in 1:91.4.0-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • thunderbird
    Fixed in 1:91.4.0-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 18.04 LTS

  • thunderbird
    Fixed in 1:91.5.0+build1-0ubuntu0.18.04.1

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • thunderbird
    Fixed in 1:91.5.0+build1-0ubuntu0.20.04.1

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.