Mozilla Thunderbird up to 91.4.0 Digital Signature

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.5$5k-$25k0.00

Summaryinfo

A vulnerability identified as problematic has been detected in Mozilla Thunderbird up to 91.4.0. Affected is an unknown function of the component Digital Signature Handler. This manipulation causes an unknown weakness. The identification of this vulnerability is CVE-2021-4126. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Mozilla Thunderbird up to 91.4.0 (Mail Client Software) and classified as problematic. Affected by this vulnerability is some unknown functionality of the component Digital Signature Handler. As an impact it is known to affect integrity, and availability. The summary by CVE is:

When receiving an OpenPGP/MIME signed email message that contains an additional outer MIME message layer, for example a message footer added by a mailing list gateway, Thunderbird only considered the inner signed message for the signature validity. This gave the false impression that the additional contents were also covered by the digital signature. Starting with Thunderbird version 91.4.1, only the signature that belongs to the top level MIME part will be considered for the displayed status. This vulnerability affects Thunderbird < 91.4.1.

The weakness was shared 12/23/2022. The advisory is shared at mozilla.org. This vulnerability is known as CVE-2021-4126 since 12/16/2021. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 04/16/2025).

Upgrading to version 91.4.1 eliminates this vulnerability. The upgrade is hosted for download at mozilla.org.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Unknown
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Thunderbird 91.4.1

Timelineinfo

12/16/2021 🔍
12/23/2022 +372 days 🔍
12/23/2022 +0 days 🔍
04/16/2025 +845 days 🔍

Sourcesinfo

Vendor: mozilla.org

Advisory: mozilla.org
Status: Confirmed

CVE: CVE-2021-4126 (🔍)
GCVE (CVE): GCVE-0-2021-4126
GCVE (VulDB): GCVE-100-216589

Entryinfo

Created: 12/23/2022 08:15
Updated: 04/16/2025 18:35
Changes: 12/23/2022 08:15 (40), 01/22/2023 17:24 (11), 04/16/2025 18:35 (15)
Complete: 🔍
Cache ID: 216::103

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