Bouncy Castle for Java up to 2.1.0 API Module BaseCipher 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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3.8$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Bouncy Castle for Java up to 2.1.0. Impacted is an unknown function of the file org/bouncycastle/jcajce/provider/BaseCipher of the component API Module. The manipulation leads to out-of-bounds write. This vulnerability is traded as CVE-2025-9340. It is possible to launch the attack on the physical device. There is no exploit available.

Detailsinfo

A vulnerability was found in Bouncy Castle for Java up to 2.1.0. It has been rated as problematic. This issue affects some unknown functionality of the file org/bouncycastle/jcajce/provider/BaseCipher of the component API Module. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Out-of-bounds Write vulnerability in Legion of the Bouncy Castle Inc. Bouncy Castle for Java bc-fips on All (API modules). This vulnerability is associated with program files org/bouncycastle/jcajce/provider/BaseCipher. This issue affects Bouncy Castle for Java: from BC-FJA 2.1.0 through 2.1.0.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2025-9340 since 08/22/2025. The exploitation is known to be easy. An attack has to be approached locally. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at EUVD (EUVD-2025-25505) and CERT Bund (WID-SEC-2025-1895). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Open Source Bouncy Castle

Productinfo

Type

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 3.9
VulDB Meta Temp Score: 3.8

VulDB Base Score: 3.9
VulDB Temp Score: 3.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: Yes
Local: Yes
Remote: Partially

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: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

08/22/2025 Advisory disclosed
08/22/2025 +0 days CVE reserved
08/22/2025 +0 days VulDB entry created
08/22/2025 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Not defined

CVE: CVE-2025-9340 (🔒)
GCVE (CVE): GCVE-0-2025-9340
GCVE (VulDB): GCVE-100-321029
EUVD: 🔒
CERT Bund: WID-SEC-2025-1895 - Bouncy Castle: Mehrere Schwachstellen

Entryinfo

Created: 08/22/2025 14:18
Updated: 08/22/2025 16:25
Changes: 08/22/2025 14:18 (70), 08/22/2025 14:37 (7), 08/22/2025 16:25 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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