Mozilla Firefox/Firefox ESR/Thunderbird IonMonkey JIT Compiler Proto Mutation type conversion

CVSS Meta Temp Score
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CTI Interest Score
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7.4$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in Mozilla Firefox, Firefox ESR and Thunderbird. This affects an unknown function of the component IonMonkey JIT Compiler. Performing a manipulation as part of Proto Mutation results in type conversion. This vulnerability is known as CVE-2019-9813. Remote exploitation of the attack is possible. Furthermore, an exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox, Firefox ESR and Thunderbird (Web Browser) (version now known). This affects some unknown processing of the component IonMonkey JIT Compiler. The manipulation as part of a Proto Mutation leads to a type conversion vulnerability. CWE is classifying the issue as CWE-704. The product does not correctly convert an object, resource, or structure from one type to a different type. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Incorrect handling of __proto__ mutations may lead to type confusion in IonMonkey JIT code and can be leveraged for arbitrary memory read and write. This vulnerability affects Firefox < 66.0.1, Firefox ESR < 60.6.1, and Thunderbird < 60.6.1.

The bug was discovered 03/22/2019. The weakness was published 04/26/2019 by Markus Vervier (Nils) with X41 D-Sec GmbH (Website). It is possible to read the advisory at access.redhat.com. This vulnerability is uniquely identified as CVE-2019-9813 since 03/14/2019. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are unknown but a public exploit is available.

The exploit is shared for download at exploit-db.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 35 days. During that time the estimated underground price was around $5k-$25k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 371702 (Mozilla Firefox Multiple Vulnerabilities(MFSA 2019-09,MFSA2019-10)).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (46646) and SecurityFocus (BID 106773†). Similar entries are available at VDB-130538, VDB-134153, VDB-134155 and VDB-134156. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.2

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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NVD Base Score: 🔍

Exploitinginfo

Class: Type conversion
CWE: CWE-704
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

01/29/2019 🔍
03/14/2019 +44 days 🔍
03/22/2019 +8 days 🔍
04/26/2019 +35 days 🔍
04/27/2019 +1 days 🔍
11/26/2025 +2405 days 🔍

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: RHSA-2019:0966
Researcher: Markus Vervier (Nils)
Organization: X41 D-Sec GmbH
Status: Confirmed

CVE: CVE-2019-9813 (🔍)
GCVE (CVE): GCVE-0-2019-9813
GCVE (VulDB): GCVE-100-134175
SecurityFocus: 106773 - Mozilla Firefox MFSA2019-01 Multiple Security Vulnerabilities

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 04/27/2019 09:42
Updated: 11/26/2025 09:54
Changes: 04/27/2019 09:42 (62), 06/03/2020 09:11 (7), 09/07/2023 20:30 (4), 02/28/2025 04:39 (23), 11/26/2025 09:54 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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