Mozilla Firefox up to 134 memory corruption

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.5$5k-$25k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Mozilla Firefox up to 134. This vulnerability affects unknown code. Performing a manipulation results in memory corruption. This vulnerability is reported as CVE-2025-1020. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 134. This affects an unknown code. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 135 and Thunderbird 135.

It is possible to read the advisory at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2025-1020 since 02/04/2025. The exploitability is told to be easy. 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. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 04/15/2026).

The vulnerability scanner Nessus provides a plugin with the ID 216055 (Ubuntu 20.04 LTS : Firefox vulnerabilities (USN-7263-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 135 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (216055). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.6
VulDB Meta Temp Score: 8.5

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

NVD Base Score: 9.8
NVD Vector: 🔍

ADP CISA Base Score: 9.8
ADP CISA Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Memory corruption
CWE: 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: 216055
Nessus Name: Ubuntu 20.04 LTS : Firefox vulnerabilities (USN-7263-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Firefox 135

Timelineinfo

02/04/2025 🔍
02/04/2025 +0 days 🔍
02/04/2025 +0 days 🔍
04/15/2026 +435 days 🔍

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2025-1020 (🔍)
GCVE (CVE): GCVE-0-2025-1020
GCVE (VulDB): GCVE-100-294627

Entryinfo

Created: 02/04/2025 15:47
Updated: 04/15/2026 09:49
Changes: 02/04/2025 15:47 (55), 02/05/2025 22:17 (3), 02/07/2025 10:18 (12), 02/11/2025 13:22 (2), 04/15/2026 09:49 (12)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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