Mozilla Firefox/Firefox ESR/Thunderbird Popup Window clickjacking

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.2$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in Mozilla Firefox, Firefox ESR and Thunderbird. Affected by this vulnerability is an unknown functionality of the component Popup Window Handler. Such manipulation leads to clickjacking. This vulnerability is referenced as CVE-2021-23984. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox, Firefox ESR and Thunderbird (Web Browser) (affected version unknown) and classified as critical. Affected by this issue is an unknown functionality of the component Popup Window Handler. The manipulation with an unknown input leads to a clickjacking vulnerability. Using CWE to declare the problem leads to CWE-451. The user interface (UI) does not properly represent critical information to the user, allowing the information - or its source - to be obscured or spoofed. This is often a component in phishing attacks. Impacted is confidentiality, integrity, and availability.

The weakness was published 03/31/2021. The advisory is shared for download at bugzilla.mozilla.org. This vulnerability is handled as CVE-2021-23984. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 01/25/2026). The MITRE ATT&CK project declares the attack technique as T1566.003.

The vulnerability scanner Nessus provides a plugin with the ID 296367 (MiracleLinux 4 : thunderbird-78.9.0-3.0.1.AXS4 (AXSA:2021-1624:05)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (296367). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
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: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Clickjacking
CWE: CWE-451
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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Nessus ID: 296367
Nessus Name: MiracleLinux 4 : thunderbird-78.9.0-3.0.1.AXS4 (AXSA:2021-1624:05)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

01/13/2021 🔍
03/31/2021 +76 days 🔍
03/31/2021 +0 days 🔍
01/25/2026 +1761 days 🔍

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-23984 (🔍)
GCVE (CVE): GCVE-0-2021-23984
GCVE (VulDB): GCVE-100-172040

Entryinfo

Created: 03/31/2021 22:01
Updated: 01/25/2026 15:48
Changes: 03/31/2021 22:01 (38), 04/07/2021 12:52 (5), 04/07/2021 12:58 (18), 01/25/2026 15:48 (17)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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