Bouncy Castle BC Java before 1.66, BC C# .NET before 1.8.7, BC-FJA before 1.0.1.2, 1.0.2.1, and BC-FNA before 1.0.1.1 have a timing issue within the EC math library that can expose information about the private key when an attacker is able to observe timing information for the generation of multiple deterministic ECDSA signatures.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.9, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), for affected systems. Impacting 4 products from bouncycastle, from bouncycastle, from bouncycastle and 1 other, organizations running these solutions should prioritize assessment and patching.
Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2021-05-20T12:15:08.003
2025-07-17T17:04:58.987
Modified
CVSSv3.1: 5.9 (MEDIUM)
AV:N/AC:M/Au:N/C:P/I:N/A:N
8.6
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | bouncycastle | bc-csharp | < 1.8.7 | Yes |
| Application | bouncycastle | bouncy_castle_fips_.net_api | < 1.0.1.1 | Yes |
| Application | bouncycastle | fips_java_api | < 1.0.1.2 | Yes |
| Application | bouncycastle | fips_java_api | < 1.0.2.1 | Yes |
| Application | bouncycastle | the_bouncy_castle_crypto_package_for_java | < 1.66 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For bouncycastle's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.