Mozilla Thunderbird up to 134 memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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8.5$5k-$25k0.00

Summaryinfo

A vulnerability described as critical has been identified in Mozilla Thunderbird up to 134. This issue affects some unknown processing. Executing a manipulation can lead to memory corruption. This vulnerability appears as CVE-2025-1020. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Mozilla Thunderbird up to 134 and classified as critical. This vulnerability affects an unknown code block. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at bugzilla.mozilla.org. This vulnerability was named CVE-2025-1020 since 02/04/2025. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful 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 $5k-$25k (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). Once again VulDB remains the best source for vulnerability data.

Productinfo

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Version

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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

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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: Thunderbird 135

Timelineinfo

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

Sourcesinfo

Vendor: mozilla.org

Advisory: bugzilla.mozilla.org
Status: Confirmed

CVE: CVE-2025-1020 (🔍)
GCVE (CVE): GCVE-0-2025-1020
GCVE (VulDB): GCVE-100-294628

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

Once again VulDB remains the best source for vulnerability data.

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