Mozilla Firefox ESR/Thunderbird up to 52.5 Event FORM Element 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.
7.9$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Mozilla Firefox ESR and Thunderbird up to 52.5. Affected is an unknown function of the component Event Handler. Such manipulation as part of FORM Element leads to use after free. This vulnerability is referenced as CVE-2018-5096. It is possible to launch the attack remotely. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Mozilla Firefox ESR and Thunderbird up to 52.5 (Mail Client Software). Affected by this issue is an unknown part of the component Event Handler. The manipulation as part of a FORM Element 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. CVE summarizes:

A use-after-free vulnerability can occur while editing events in form elements on a page, resulting in a potentially exploitable crash. This vulnerability affects Firefox ESR < 52.6 and Thunderbird < 52.6.

The bug was discovered 01/23/2018. The weakness was published 06/11/2018 by Nils as Bug 1418922 as not defined bug report (Bugzilla). The advisory is shared for download at bugzilla.mozilla.org. This vulnerability is handled as CVE-2018-5096 since 01/03/2018. The attack may be launched remotely. No form of authentication is required for exploitation. 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 11/26/2025).

The vulnerability scanner Nessus provides a plugin with the ID 106300 (Mozilla Firefox ESR < 52.6 Multiple Vulnerabilities (macOS)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family MacOS X Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 157636 (Oracle Enterprise Linux Security Update for firefox (ELSA-2018-0122)).

Upgrading to version 52.6 eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (106300) and SecurityFocus (BID 102771†). Similar entries are available at VDB-112518, VDB-112522, VDB-112523 and VDB-112525. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

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

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

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-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 106300
Nessus Name: Mozilla Firefox ESR < 52.6 Multiple Vulnerabilities (macOS)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 66413
OpenVAS Name: CentOS Update for firefox CESA-2018:0122 centos6
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Firefox ESR/Thunderbird 52.6

Timelineinfo

01/03/2018 🔍
01/23/2018 +20 days 🔍
01/23/2018 +0 days 🔍
01/23/2018 +0 days 🔍
01/24/2018 +1 days 🔍
06/11/2018 +137 days 🔍
06/11/2018 +0 days 🔍
06/12/2018 +1 days 🔍
11/26/2025 +2724 days 🔍

Sourcesinfo

Vendor: mozilla.org

Advisory: Bug 1418922
Researcher: Nils
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-5096 (🔍)
GCVE (CVE): GCVE-0-2018-5096
GCVE (VulDB): GCVE-100-119360

OVAL: 🔍

SecurityFocus: 102771 - Mozilla Firefox ESR CVE-2018-5096 Use After Free Denial of Service Vulnerability

See also: 🔍

Entryinfo

Created: 06/12/2018 10:17
Updated: 11/26/2025 06:37
Changes: 06/12/2018 10:17 (80), 02/18/2020 09:24 (5), 11/26/2025 06:37 (19)
Complete: 🔍
Cache ID: 216::103

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

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you know our Splunk app?

Download it now for free!