SynopsisThe remote Debian host is missing a security update.
DescriptionSeveral vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks.
Shi Lei discovered that RxRPC Kerberos 5 ticket handling code does not properly verify metadata, leading to information disclosure, denial of service or potentially execution of arbitrary code.
An integer overflow vulnerability in the ip6_find_1stfragopt() function was found allowing a local attacker with privileges to open raw sockets to cause a denial of service.
Tommi Rantala and Brad Spengler reported that the mm subsystem does not properly enforce the CONFIG_STRICT_DEVMEM protection mechanism, allowing a local attacker with access to /dev/mem to obtain sensitive information or potentially execute arbitrary code.
Dmitry Vyukov of Google reported that the timerfd facility does not properly handle certain concurrent operations on a single file descriptor. This allows a local attacker to cause a denial of service or potentially to execute arbitrary code.
CVE-2017-10911 / XSA-216
Anthony Perard of Citrix discovered an information leak flaw in Xen blkif response handling, allowing a malicious unprivileged guest to obtain sensitive information from the host or other guests.
It was discovered that the mq_notify() function does not set the sock pointer to NULL upon entry into the retry logic. An attacker can take advantage of this flaw during a userspace close of a Netlink socket to cause a denial of service or potentially cause other impact.
bo Zhang reported that the xfrm subsystem does not properly validate one of the parameters to a netlink message. Local users with the CAP_NET_ADMIN capability can use this to cause a denial of service or potentially to execute arbitrary code.
CVE-2017-12134 / #866511 / XSA-229
Jan H. Schönherr of Amazon discovered that when Linux is running in a Xen PV domain on an x86 system, it may incorrectly merge block I/O requests. A buggy or malicious guest may trigger this bug in dom0 or a PV driver domain, causing a denial of service or potentially execution of arbitrary code.
This issue can be mitigated by disabling merges on the underlying back-end block devices, e.g.: echo 2 > /sys/block/nvme0n1/queue/nomerges
bo Zhang reported that the cfg80211 (wifi) subsystem does not properly validate the parameters to a netlink message. Local users with the CAP_NET_ADMIN capability on a system with a wifi device can use this to cause a denial of service.
Jim Mattson of Google reported that the KVM implementation for Intel x86 processors did not correctly handle certain nested hypervisor configurations. A malicious guest (or nested guest in a suitable L1 hypervisor) could use this for denial of service.
Andrey Konovalov of Google reported that a specific sequence of operations on a TCP socket could lead to division by zero. A local user could use this for denial of service.
Otto Ebeling reported that the move_pages() system call permitted users to discover the memory layout of a set-UID process running under their real user-ID. This made it easier for local users to exploit vulnerabilities in programs installed with the set-UID permission bit set.
'sohu0106' reported an information leak in the atyfb video driver. A local user with access to a framebuffer device handled by this driver could use this to obtain sensitive information.
Richard Wareing discovered that the XFS implementation allows the creation of files with the 'realtime' flag on a filesystem with no realtime device, which can result in a crash (oops). A local user with access to an XFS filesystem that does not have a realtime device can use this for denial of service.
ChunYu of Red Hat discovered that the iSCSI subsystem does not properly validate the length of a netlink message, leading to memory corruption. A local user with permission to manage iSCSI devices can use this for denial of service or possibly to execute arbitrary code.
Andrey Konovalov of Google reported that a race condition in the raw packet (af_packet) feature. Local users with the CAP_NET_RAW capability can use this to cause a denial of service or possibly to execute arbitrary code.
CVE-2017-1000251 / #875881
Armis Labs discovered that the Bluetooth subsystem does not properly validate L2CAP configuration responses, leading to a stack buffer overflow. This is one of several vulnerabilities dubbed 'Blueborne'. A nearby attacker can use this to cause a denial of service or possibly to execute arbitrary code on a system with Bluetooth enabled.
Roee Hay reported that the lp driver does not properly bounds-check passed arguments. This has no security impact in Debian.
It was discovered that argument and environment pointers are not properly taken into account by the size restrictions on arguments and environmental strings passed through execve(). A local attacker can take advantage of this flaw in conjunction with other flaws to execute arbitrary code.
Alexander Potapenko of Google reported a race condition in the ALSA (sound) timer driver, leading to an information leak. A local user with permission to access sound devices could use this to obtain sensitive information.
For Debian 7 'Wheezy', these problems have been fixed in version 3.2.93-1. This version also includes bug fixes from upstream versions up to and including 3.2.93.
For Debian 8 'Jessie', these problems have been fixed in version 3.16.43-2+deb8u4 or were fixed in an earlier version.
For Debian 9 'Stretch', these problems have been fixed in version 4.9.30-2+deb9u4 or were fixed in an earlier version.
We recommend that you upgrade your linux packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpgrade the affected linux package.