[SECURITY] [DLA 187-1] tor security update

Package : tor
Version : 0.2.4.27-1~deb6u1
CVE ID : CVE-2015-2928 CVE-2015-2929

Several hidden service related denial-of-service issues have been
discovered in Tor, a connection-based low-latency anonymous
communication system.

o "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-2015-2928]

o "DonnchaC" discovered that Tor clients would crash with an assertion
failure upon parsing specially crafted hidden service descriptors.
[CVE-2015-2929]

o 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 no longer allow
multiple such cells on the same circuit.