VDB-245909 · CVE-2023-6207 · Nessus 239860

Mozilla Thunderbird ReadableByteStreams use after free

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.4	$5k-$25k	0.00

Summaryinfo

A vulnerability classified as critical has been found in Mozilla Thunderbird. This issue affects the function ReadableByteStreams. The manipulation leads to use after free. This vulnerability is traded as CVE-2023-6207. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Mozilla Thunderbird (Mail Client Software) (version now known). This issue affects the function ReadableByteStreams. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Ownership mismanagement led to a use-after-free in ReadableByteStreams This vulnerability affects Firefox < 120, Firefox < 115.5, and Thunderbird < 115.5.0.

The weakness was shared 11/21/2023. The advisory is shared at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2023-6207 since 11/20/2023. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/19/2025).

The vulnerability scanner Nessus provides a plugin with the ID 239860 (TencentOS Server 2: firefox (TSSA-2023:0316)), 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 (239860). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Mail Client Software

Vendor

Mozilla

Name

Thunderbird

License

open-source

Website

Vendor: https://www.mozilla.org/

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

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 239860
Nessus Name: TencentOS Server 2: firefox (TSSA-2023:0316)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

11/20/2023 🔍
11/21/2023 +1 days 🔍
11/21/2023 +0 days 🔍
06/19/2025 +576 days 🔍

Sourcesinfo

Vendor: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2023-6207 (🔍)
GCVE (CVE): GCVE-0-2023-6207
GCVE (VulDB): GCVE-100-245909

Entryinfo

Created: 11/21/2023 16:14
Updated: 06/19/2025 14:53
Changes: 11/21/2023 16:14 (38), 12/15/2023 11:17 (11), 06/19/2025 14:53 (17)
Complete: 🔍
Cache ID: 216::103

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