Mozilla Firefox up to 109 EncodeInputStream out-of-bounds write

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.9$5k-$25k0.00

Summaryinfo

A vulnerability was found in Mozilla Firefox up to 109. It has been rated as critical. Affected by this issue is the function EncodeInputStream. Performing a manipulation results in out-of-bounds write. This vulnerability is identified as CVE-2023-25732. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in Mozilla Firefox up to 109 (Web Browser). This affects the function EncodeInputStream. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

When encoding data from an <code>inputStream</code> in <code>xpcom</code> the size of the input being encoded was not correctly calculated potentially leading to an out of bounds memory write. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.

The weakness was released 02/14/2023 by Ronald Crane as Bug 1804564 as confirmed advisory (Website). The advisory is shared at bugzilla.mozilla.org. The advisory contains:

When encoding data from an inputStream in xpcom the size of the input being encoded was not correctly calculated potentially leading to an out of bounds memory write.
This vulnerability is uniquely identified as CVE-2023-25732. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 11/01/2025).

Upgrading to version 110 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-29639). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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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: 8.8
NVD Vector: 🔍

CNA Base Score: 8.8
CNA Vector: 🔍

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / 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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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: Firefox 110

Timelineinfo

02/13/2023 🔍
02/14/2023 +1 days 🔍
02/14/2023 +0 days 🔍
03/02/2023 +16 days 🔍
11/01/2025 +975 days 🔍

Sourcesinfo

Vendor: mozilla.org
Product: mozilla.org

Advisory: Bug 1804564
Researcher: Ronald Crane
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2023-25732 (🔍)
GCVE (CVE): GCVE-0-2023-25732
GCVE (VulDB): GCVE-100-222201
EUVD: 🔍

Entryinfo

Created: 03/02/2023 15:12
Updated: 11/01/2025 21:53
Changes: 03/02/2023 15:12 (17), 03/02/2023 15:15 (29), 03/30/2023 16:14 (1), 01/09/2025 22:44 (36), 04/27/2025 20:47 (3), 11/01/2025 21:53 (1)
Complete: 🔍
Cache ID: 216::103

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

Discussion

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