Debian: DSA-3659-1 Significant: Kernel Escalation Vulnerabilities

CVE-2016-5696

Yue Cao, Zhiyun Qian, Zhongjie Wang, Tuan Dao, and Srikanth V.
Krishnamurthy of the University of California, Riverside; and Lisa
M. Marvel of the United States Army Research Laboratory discovered
that Linux's implementation of the TCP Challenge ACK feature
results in a side channel that can be used to find TCP connections
between specific IP addresses, and to inject messages into those
connections.

Where a service is made available through TCP, this may allow
remote attackers to impersonate another connected user to the
server or to impersonate the server to another connected user. In
case the service uses a protocol with message authentication
(e.g. TLS or SSH), this vulnerability only allows denial of
service (connection failure). An attack takes tens of seconds, so
short-lived TCP connections are also unlikely to be vulnerable.

This may be mitigated by increasing the rate limit for TCP
Challenge ACKs so that it is n...