MEDIUM · CVSS 5.9

CVE-2024-30171 — Bouncy Castle timing side-channel

A timing side-channel in Bouncy Castle's RSA-PKCS#1 v1.5 implementation could allow an attacker to recover key material or plaintext through repeated oracle queries.

Affects
  • Bouncy Castle Java < 1.78

What an attacker does

Applications using Bouncy Castle for RSA decryption with PKCS#1 v1.5 padding leaked timing signals. An attacker with the ability to send ciphertexts and measure response time could mount a Bleichenbacher-style attack.

How to detect

Check the Java dependency graph.

How to fix

Upgrade Bouncy Castle to 1.78+. Prefer OAEP over PKCS#1 v1.5 where possible.

How Securie catches it

Securie's Java + crypto scanner flags vulnerable BC versions in auth paths.

References