tor - security update

Several vulnerabilities have been discovered in Tor, a connection-based
low-latency anonymous communication system:

• CVE-2015-2928
  disgleirio discovered that a malicious client could trigger an
  assertion failure in a Tor instance providing a hidden service,
  thus rendering the service inaccessible.
• CVE-2015-2929
  DonnchaC discovered that Tor clients would crash with an
  assertion failure upon parsing specially crafted hidden service
  descriptors.

Introduction points would accept multiple INTRODUCE1 cells on one
circuit, making it inexpensive for an attacker to overload a hidden
service with introductions. Introduction points now no longer allow
multiple cells of that type on the same circuit.

For the stable distribution (wheezy), these problems have been fixed in
version 0.2.4.27-1.

For the unstable distribution (sid), these problems have been fixed in
version 0.2.5.12-1.

For the experimental distribution, these problems have been
fixed in version 0.2.6.7-1.

We recommend that you upgrade your tor packages.