Tibor Jager, Jörg Schwenk, and Juraj Somorovsky, from Horst Görtz Institute for IT Security, published a paper in ESORICS 2015 where they describe an invalid curve attack in Bouncy Castle Crypto, a Java library for cryptography. An attacker is able to recover private Elliptic Curve keys from different applications, for example, TLS servers.
More information: <http://web-in-security.blogspot.ca/2015/09/practical-invalid-curve-attacks.html>
Practical Invalid Curve Attacks on TLS-ECDH: <http://euklid.org/pdf/ECC_Invalid_Curve.pdf>
For the oldstable distribution (wheezy), this problem has been fixed in version 1.44+dfsg-3.1+deb7u1.
For the stable distribution (jessie), this problem has been fixed in version 1.49+dfsg-3+deb8u1.
For the unstable distribution (sid), this problem has been fixed in version 1.51-2.
We recommend that you upgrade your bouncycastle packages.