BouncyCastle TLS prior to version 1.0.3, when configured to use the JCE (Java Cryptography Extension) for cryptographic functions, provides a weak Bleichenbacher oracle when any TLS cipher suite using RSA key exchange is negotiated. An attacker can recover the private key from a vulnerable application. This vulnerability is referred to as "ROBOT."
Created bouncycastle tracking bugs for this issue:
Affects: fedora-all [bug 1525531]
This issue affects the versions of bouncycastle as shipped with Red Hat Subscription Asset Manager version 1 and Satellite version 6. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
This issue affects the bctls component / jar, which was only added in Bouncy Castle version 1.56, as noted in the release notes for the version:
A higher level TLS API and JSSE provider have been added to the project.
The affected code is not included in the bouncycastle packages that only contain the bcprov component. Note that the bcprov component contains another TLS implementation, which was explicitly noted as not affected by this flaw:
Note that the older TLS implementation (in the org.bouncycastle.crypto.tls package) is not vulnerable.
In reply to comment 0:
> BouncyCastle TLS prior to version 1.0.3, ...
This version is misleading and refers to Bouncy Castle FIPS versions - or bctls-fips component specifically - and not the mainline non-FIPS Bouncy Castle, which was fixed in version 1.59.