Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks. CVE-2015-7515, CVE-2016-2184, CVE-2016-2185, CVE-2016-2186, CVE-2016-2187, CVE-2016-3136, CVE-2016-3137, CVE-2016-3138, CVE-2016-3140 Ralf Spenneberg of OpenSource Security reported that various USB drivers do not sufficiently validate USB descriptors. This allowed a physically present user with a specially designed USB device to cause a denial of service (crash). CVE-2016-0821 Solar Designer noted that the list poisoning feature, intended to mitigate the effects of bugs in list manipulation in the kernel, used poison values within the range of virtual addresses that can be allocated by user processes. CVE-2016-1237 David Sinquin discovered that nfsd does not check permissions when setting ACLs, allowing users to grant themselves permissions to a file by setting the ACL. CVE-2016-1583 Jann Horn of Google Project Zero reported that the eCryptfs filesystem could be used together with the proc filesystem to cause a kernel stack overflow. If the ecryptfs-utils package is installed, local users could exploit this, via the mount.ecryptfs_private program, for denial of service (crash) or possibly for privilege escalation. CVE-2016-2117 Justin Yackoski of Cryptonite discovered that the Atheros L2 ethernet driver incorrectly enables scatter/gather I/O. A remote attacker could take advantage of this flaw to obtain potentially sensitive information from kernel memory. CVE-2016-2143 Marcin Koscielnicki discovered that the fork implementation in the Linux kernel on s390 platforms mishandles the case of four page-table levels, which allows local users to cause a denial of service (system crash). CVE-2016-3070 Jan Stancek of Red Hat discovered a local denial of service vulnerability in AIO handling. CVE-2016-3134 The Google Project Zero team found that the netfilter subsystem does not sufficiently validate filter table entries. A user with the CAP_NET_ADMIN capability could use this for denial of service (crash) or possibly for privilege escalation. Debian disables unprivileged user namespaces by default, if locally enabled with the kernel.unprivileged_userns_clone sysctl, this allows privilege escalation. CVE-2016-3156 Solar Designer discovered that the IPv4 implementation in the Linux kernel did not perform the destruction of inet device objects properly. An attacker in a guest OS could use this to cause a denial of service (networking outage) in the host OS. CVE-2016-3157 / XSA-171 Andy Lutomirski discovered that the x86_64 (amd64) task switching implementation did not correctly update the I/O permission level when running as a Xen paravirtual (PV) guest. In some configurations this would allow local users to cause a denial of service (crash) or to escalate their privileges within the guest. CVE-2016-3672 Hector Marco and Ismael Ripoll noted that it was possible to disable Address Space Layout Randomisation (ASLR) for x86_32 (i386) programs by removing the stack resource limit. This made it easier for local users to exploit security flaws in programs that have the setuid or setgid flag set. CVE-2016-3951 It was discovered that the cdc_ncm driver would free memory prematurely if certain errors occurred during its initialisation. This allowed a physically present user with a specially designed USB device to cause a denial of service (crash) or possibly to escalate their privileges. CVE-2016-3955 Ignat Korchagin reported that the usbip subsystem did not check the length of data received for a USB buffer. This allowed denial of service (crash) or privilege escalation on a system configured as a usbip client, by the usbip server or by an attacker able to impersonate it over the network. A system configured as a usbip server might be similarly vulnerable to physically present users. CVE-2016-3961 / XSA-174 Vitaly Kuznetsov of Red Hat discovered that Linux allowed the use of hugetlbfs on x86 (i386 and amd64) systems even when running as a Xen paravirtualised (PV) guest, although Xen does not support huge pages. This allowed users with access to /dev/hugepages to cause a denial of service (crash) in the guest. CVE-2016-4470 David Howells of Red Hat discovered that a local user can trigger a flaw in the Linux kernel's handling of key lookups in the keychain subsystem, leading to a denial of service (crash) or possibly to privilege escalation. CVE-2016-4482, CVE-2016-4485, CVE-2016-4486, CVE-2016-4569, CVE-2016-4578, CVE-2016-4580, CVE-2016-5243, CVE-2016-5244 Kangjie Lu reported that the USB devio, llc, rtnetlink, ALSA timer, x25, tipc, and rds facilities leaked information from the kernel stack. CVE-2016-4565 Jann Horn of Google Project Zero reported that various components in the InfiniBand stack implemented unusual semantics for the write() operation. On a system with InfiniBand drivers loaded, local users could use this for denial of service or privilege escalation. CVE-2016-4581 Tycho Andersen discovered that in some situations the Linux kernel did not handle propagated mounts correctly. A local user can take advantage of this flaw to cause a denial of service (system crash). CVE-2016-4805 Baozeng Ding discovered a use-after-free in the generic PPP layer in the Linux kernel. A local user can take advantage of this flaw to cause a denial of service (system crash), or potentially escalate their privileges. CVE-2016-4913 Al Viro found that the ISO9660 filesystem implementation did not correctly count the length of certain invalid name entries. Reading a directory containing such name entries would leak information from kernel memory. Users permitted to mount disks or disk images could use this to obtain sensitive information. CVE-2016-4997 / CVE-2016-4998 Jesse Hertz and Tim Newsham discovered that missing input sanitising in Netfilter socket handling may result in denial of service. Debian disables unprivileged user namespaces by default, if locally enabled with the kernel.unprivileged_userns_clone sysctl, this also allows privilege escalation. For the stable distribution (jessie), these problems have been fixed in version 3.16.7-ckt25-2+deb8u2. We recommend that you upgrade your linux packages.
Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks.
Ralf Spenneberg of OpenSource Security reported that various USB drivers do not sufficiently validate USB descriptors. This allowed a physically present user with a specially designed USB device to cause a denial of service (crash).
Solar Designer noted that the list poisoning
feature, intended
to mitigate the effects of bugs in list manipulation in the
kernel, used poison values within the range of virtual addresses
that can be allocated by user processes.
David Sinquin discovered that nfsd does not check permissions when setting ACLs, allowing users to grant themselves permissions to a file by setting the ACL.
Jann Horn of Google Project Zero reported that the eCryptfs filesystem could be used together with the proc filesystem to cause a kernel stack overflow. If the ecryptfs-utils package is installed, local users could exploit this, via the mount.ecryptfs_private program, for denial of service (crash) or possibly for privilege escalation.
Justin Yackoski of Cryptonite discovered that the Atheros L2 ethernet driver incorrectly enables scatter/gather I/O. A remote attacker could take advantage of this flaw to obtain potentially sensitive information from kernel memory.
Marcin Koscielnicki discovered that the fork implementation in the Linux kernel on s390 platforms mishandles the case of four page-table levels, which allows local users to cause a denial of service (system crash).
Jan Stancek of Red Hat discovered a local denial of service vulnerability in AIO handling.
The Google Project Zero team found that the netfilter subsystem does not sufficiently validate filter table entries. A user with the CAP_NET_ADMIN capability could use this for denial of service (crash) or possibly for privilege escalation. Debian disables unprivileged user namespaces by default, if locally enabled with the kernel.unprivileged_userns_clone sysctl, this allows privilege escalation.
Solar Designer discovered that the IPv4 implementation in the Linux kernel did not perform the destruction of inet device objects properly. An attacker in a guest OS could use this to cause a denial of service (networking outage) in the host OS.
Andy Lutomirski discovered that the x86_64 (amd64) task switching implementation did not correctly update the I/O permission level when running as a Xen paravirtual (PV) guest. In some configurations this would allow local users to cause a denial of service (crash) or to escalate their privileges within the guest.
Hector Marco and Ismael Ripoll noted that it was possible to disable Address Space Layout Randomisation (ASLR) for x86_32 (i386) programs by removing the stack resource limit. This made it easier for local users to exploit security flaws in programs that have the setuid or setgid flag set.
It was discovered that the cdc_ncm driver would free memory prematurely if certain errors occurred during its initialisation. This allowed a physically present user with a specially designed USB device to cause a denial of service (crash) or possibly to escalate their privileges.
Ignat Korchagin reported that the usbip subsystem did not check the length of data received for a USB buffer. This allowed denial of service (crash) or privilege escalation on a system configured as a usbip client, by the usbip server or by an attacker able to impersonate it over the network. A system configured as a usbip server might be similarly vulnerable to physically present users.
Vitaly Kuznetsov of Red Hat discovered that Linux allowed the use of hugetlbfs on x86 (i386 and amd64) systems even when running as a Xen paravirtualised (PV) guest, although Xen does not support huge pages. This allowed users with access to /dev/hugepages to cause a denial of service (crash) in the guest.
David Howells of Red Hat discovered that a local user can trigger a flaw in the Linux kernel's handling of key lookups in the keychain subsystem, leading to a denial of service (crash) or possibly to privilege escalation.
Kangjie Lu reported that the USB devio, llc, rtnetlink, ALSA timer, x25, tipc, and rds facilities leaked information from the kernel stack.
Jann Horn of Google Project Zero reported that various components in the InfiniBand stack implemented unusual semantics for the write() operation. On a system with InfiniBand drivers loaded, local users could use this for denial of service or privilege escalation.
Tycho Andersen discovered that in some situations the Linux kernel did not handle propagated mounts correctly. A local user can take advantage of this flaw to cause a denial of service (system crash).
Baozeng Ding discovered a use-after-free in the generic PPP layer in the Linux kernel. A local user can take advantage of this flaw to cause a denial of service (system crash), or potentially escalate their privileges.
Al Viro found that the ISO9660 filesystem implementation did not correctly count the length of certain invalid name entries. Reading a directory containing such name entries would leak information from kernel memory. Users permitted to mount disks or disk images could use this to obtain sensitive information.
Jesse Hertz and Tim Newsham discovered that missing input sanitising in Netfilter socket handling may result in denial of service. Debian disables unprivileged user namespaces by default, if locally enabled with the kernel.unprivileged_userns_clone sysctl, this also allows privilege escalation.
For the stable distribution (jessie), these problems have been fixed in version 3.16.7-ckt25-2+deb8u2.
We recommend that you upgrade your linux packages.
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