SynopsisThe remote Debian host is missing a security-related update.
DescriptionSeveral vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or have other impacts.
- CVE-2016-9588 Jim Mattson discovered that the KVM implementation for Intel x86 processors does not properly handle #BP and #OF exceptions in an L2 (nested) virtual machine. A local attacker in an L2 guest VM can take advantage of this flaw to cause a denial of service for the L1 guest VM.
- CVE-2017-2636 Alexander Popov discovered a race condition flaw in the n_hdlc line discipline that can lead to a double free. A local unprivileged user can take advantage of this flaw for privilege escalation. On systems that do not already have the n_hdlc module loaded, this can be mitigated by disabling it:echo >> /etc/modprobe.d/disable-n_hdlc.conf install n_hdlc false
- CVE-2017-5669 Gareth Evans reported that privileged users can map memory at address 0 through the shmat() system call.
This could make it easier to exploit other kernel security vulnerabilities via a set-UID program.
- CVE-2017-5986 Alexander Popov reported a race condition in the SCTP implementation that can be used by local users to cause a denial-of-service (crash). The initial fix for this was incorrect and introduced further security issues ( CVE-2017-6353 ). This update includes a later fix that avoids those. On systems that do not already have the sctp module loaded, this can be mitigated by disabling it:echo >> /etc/modprobe.d/disable-sctp.conf install sctp false
- CVE-2017-6214 Dmitry Vyukov reported a bug in the TCP implementation's handling of urgent data in the splice() system call.
This can be used by a remote attacker for denial-of-service (hang) against applications that read from TCP sockets with splice().
- CVE-2017-6345 Andrey Konovalov reported that the LLC type 2 implementation incorrectly assigns socket buffer ownership. This can be used by a local user to cause a denial-of-service (crash). On systems that do not already have the llc2 module loaded, this can be mitigated by disabling it:echo >> /etc/modprobe.d/disable-llc2.conf install llc2 false
- CVE-2017-6346 Dmitry Vyukov reported a race condition in the raw packet (af_packet) fanout feature. Local users with the CAP_NET_RAW capability (in any user namespace) can use this for denial-of-service and possibly for privilege escalation.
- CVE-2017-6348 Dmitry Vyukov reported that the general queue implementation in the IrDA subsystem does not properly manage multiple locks, possibly allowing local users to cause a denial-of-service (deadlock) via crafted operations on IrDA devices.
SolutionUpgrade the linux packages.
For the stable distribution (jessie), these problems have been fixed in version 3.16.39-1+deb8u2.
File Name: debian_DSA-3804.nasl
Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Nessus Agent
CPE: p-cpe:/a:debian:debian_linux:linux, cpe:/o:debian:debian_linux:8.0
Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l
Patch Publication Date: 3/8/2017
Vulnerability Publication Date: 12/28/2016