Mozilla Thunderbird up to 115.0 Workers use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.4$5k-$25k0.00

Summaryinfo

A vulnerability was found in Mozilla Thunderbird up to 115.0. It has been rated as critical. This affects an unknown function of the component Workers. Performing a manipulation results in use after free. This vulnerability is identified as CVE-2023-3600. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Mozilla Thunderbird up to 115.0 (Mail Client Software). It has been classified as critical. This affects an unknown function of the component Workers. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

During the worker lifecycle, a use-after-free condition could have occurred, which could have led to a potentially exploitable crash. This vulnerability affects Firefox < 115.0.2, Firefox ESR < 115.0.2, and Thunderbird < 115.0.1.

The weakness was released 07/20/2023 by Andrew McCreight as Bug 1839703 as confirmed advisory (Website). The advisory is shared at bugzilla.mozilla.org. The advisory contains:

During the worker lifecycle, a use-after-free condition could have occured, which could have led to a potentially exploitable crash.
This vulnerability is uniquely identified as CVE-2023-3600. It demands that the victim is doing some kind of user interaction. 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 12/18/2025).

The vulnerability scanner Nessus provides a plugin with the ID 239741 (TencentOS Server 3: firefox (TSSA-2023:0238)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 115.0.1 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (239741). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

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

NVD Base Score: 8.8
NVD Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
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: 239741
Nessus Name: TencentOS Server 3: firefox (TSSA-2023:0238)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: Thunderbird 115.0.1

Timelineinfo

07/10/2023 🔍
07/20/2023 +10 days 🔍
07/20/2023 +0 days 🔍
07/24/2023 +4 days 🔍
12/18/2025 +878 days 🔍

Sourcesinfo

Vendor: mozilla.org

Advisory: Bug 1839703
Researcher: Andrew McCreight
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2023-3600 (🔍)
GCVE (CVE): GCVE-0-2023-3600
GCVE (VulDB): GCVE-100-235221

Entryinfo

Created: 07/24/2023 14:54
Updated: 12/18/2025 20:58
Changes: 07/24/2023 14:54 (18), 07/24/2023 14:57 (28), 08/16/2023 09:22 (2), 08/16/2023 09:25 (11), 06/21/2025 11:19 (17), 12/18/2025 20:58 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

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