Mozilla Firefox Garbage Collection 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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6.2$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Mozilla Firefox. Impacted is an unknown function of the component Garbage Collection. Performing a manipulation results in use after free. This vulnerability is known as CVE-2023-5171. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox (Web Browser) (affected version unknown). This affects an unknown functionality of the component Garbage Collection. 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 Ion compilation, a Garbage Collection could have resulted in a use-after-free condition, allowing an attacker to write two NUL bytes, and cause a potentially exploitable crash. This vulnerability affects Firefox < 118, Firefox ESR < 115.3, and Thunderbird < 115.3.

The weakness was published 09/27/2023. The advisory is shared at mozilla.org. This vulnerability is uniquely identified as CVE-2023-5171 since 09/25/2023. 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 06/21/2025).

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 eliminates this vulnerability. The upgrade is hosted for download at mozilla.org.

The vulnerability is also documented in the vulnerability database at Tenable (239741). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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: 🔍

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: 🔍

0-Day Time: 🔍

Upgrade: mozilla.org

Timelineinfo

09/25/2023 🔍
09/27/2023 +2 days 🔍
09/27/2023 +0 days 🔍
06/21/2025 +633 days 🔍

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: DLA 3587-1
Status: Confirmed

CVE: CVE-2023-5171 (🔍)
GCVE (CVE): GCVE-0-2023-5171
GCVE (VulDB): GCVE-100-240465

Entryinfo

Created: 09/27/2023 18:20
Updated: 06/21/2025 11:19
Changes: 09/27/2023 18:20 (39), 10/19/2023 09:56 (1), 10/19/2023 09:58 (11), 06/21/2025 11:19 (17)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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