The icmp_check_sysrq function in net/ipv4/icmp.c in the kernel.org projects/rt patches for the Linux kernel, as used in the kernel-rt package before 3.10.0-327.22.1 in Red Hat Enterprise Linux for Real Time 7 and other products, allows remote attackers to execute SysRq commands via crafted ICMP Echo Request packets, as demonstrated by a brute-force attack to discover a cookie, or an attack that occurs after reading the local icmp_echo_sysrq file.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - The icmp_check_sysrq function in net/ipv4/icmp.c in the kernel.org projects/rt patches for the Linux     kernel, as used in the kernel-rt package before 3.10.0-327.22.1 in Red Hat Enterprise Linux for Real Time     7 and other products, allows remote attackers to execute SysRq commands via crafted ICMP Echo Request     packets, as demonstrated by a brute-force attack to discover a cookie, or an attack that occurs after     reading the local icmp_echo_sysrq file. (CVE-2016-3707)

Note that Nessus relies on the presence of the package as reported by the vendor.

An update for kernel-rt is now available for Red Hat Enterprise MRG 2.5.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The kernel-rt package contain the Linux kernel, the core of any Linux operating system.

This update provides a build of the kernel-rt package for Red Hat Enterprise MRG 2.5 that is layered on Red Hat Enterprise Linux 6, and provides a number of bug fixes including :

* [netdrv] ixgbevf: fix spoofed packets with random MAC and use ether_addr_copy instead of memcpy

* [mm] mmu_notifier: fix memory corruption

* [mm] hugetlbfs: optimize when NUMA=n

* [mm] optimize put_mems_allowed() usage

* [x86] mm: suitable memory should go to ZONE_MOVABLE

* [fs] xfs: fix splice/direct-IO deadlock

* [acpi] tables: Add acpi_subtable_proc to ACPI table parsers

* [acpi] table: Add new function to get table entries

* [net] ipv6: Nonlocal bind

* [net] ipv4: bind ip_nonlocal_bind to current netns

(BZ#1332298)

Security Fix(es) :

* A flaw was found in the way certain interfaces of the Linux kernel's Infiniband subsystem used write() as bi-directional ioctl() replacement, which could lead to insufficient memory security checks when being invoked using the splice() system call. A local unprivileged user on a system with either Infiniband hardware present or RDMA Userspace Connection Manager Access module explicitly loaded, could use this flaw to escalate their privileges on the system.
(CVE-2016-4565, Important)

* A race condition flaw was found in the way the Linux kernel's SCTP implementation handled sctp_accept() during the processing of heartbeat timeout events. A remote attacker could use this flaw to prevent further connections to be accepted by the SCTP server running on the system, resulting in a denial of service. (CVE-2015-8767, Moderate)

* A flaw was found in the way the realtime kernel processed specially crafted ICMP echo requests. A remote attacker could use this flaw to trigger a sysrql function based on values in the ICMP packet, allowing them to remotely restart the system. Note that this feature is not enabled by default and requires elevated privileges to be configured.
(CVE-2016-3707, Moderate)

Red Hat would like to thank Jann Horn for reporting CVE-2016-4565.

Bug Fix(es) :

* An oops can occur in the hpsa driver while submitting ioaccel2 commands when the phys_disk pointer is NULL (in hpsa_scsi_ioaccel_raid_map). Configuration changes during I/O operations could set the phys_disk pointer to NULL. In this case, send the command down the RAID path for correct processing, avoiding the oops. (BZ#1334260)

* A faulty code merge left an extra spin_lock operation in the function fscache_invalidate_write(). The code has been correctly updated to remove this extra lock operation, which avoids a potential deadlock situation when looping through cache pages. (BZ#1327730)

An update for kernel-rt is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The kernel-rt packages contain the Linux kernel, the core of any Linux operating system.

The following packages have been upgraded to a newer upstream version:
kernel-rt (3.10.0-327.22.1). This version provides a number of bug fixes and enhancements, including :

* [netdrv] ixgbevf: fix spoofed packets with random MAC and use ether_addr_copy instead of memcpy

* [mm] mmu_notifier: fix memory corruption

* [mm] hugetlbfs: optimize when NUMA=n

* [mm] optimize put_mems_allowed() usage

* [x86] mm: suitable memory should go to ZONE_MOVABLE

* [fs] xfs: fix splice/direct-IO deadlock

* [acpi] tables: Add acpi_subtable_proc to ACPI table parsers

* [acpi] table: Add new function to get table entries

* [net] ipv6: Nonlocal bind

* [net] ipv4: bind ip_nonlocal_bind to current netns

(BZ#1335747)

Security Fix(es) :

* A flaw was found in the way certain interfaces of the Linux kernel's Infiniband subsystem used write() as bi-directional ioctl() replacement, which could lead to insufficient memory security checks when being invoked using the the splice() system call. A local unprivileged user on a system with either Infiniband hardware present or RDMA Userspace Connection Manager Access module explicitly loaded, could use this flaw to escalate their privileges on the system.
(CVE-2016-4565, Important)

* A race condition flaw was found in the way the Linux kernel's SCTP implementation handled sctp_accept() during the processing of heartbeat timeout events. A remote attacker could use this flaw to prevent further connections to be accepted by the SCTP server running on the system, resulting in a denial of service. (CVE-2015-8767, Moderate)

* A flaw was found in the way the realtime kernel processed specially crafted ICMP echo requests. A remote attacker could use this flaw to trigger a sysrql function based on values in the ICMP packet, allowing them to remotely restart the system. Note that this feature is not enabled by default and requires elevated privileges to be configured.
(CVE-2016-3707, Moderate)

Red Hat would like to thank Jann Horn for reporting CVE-2016-4565.

Bug Fix(es) :

* Previously, configuration changes to the Hewlett Packard Smart Array (HPSA) driver during I/O operations could set the phys_disk pointer to NULL. Consequently, kernel oops could occur while the HPSA driver was submitting ioaccel2 commands. An upstream patch has been provided to fix this bug, and the oops in the hpsa_scsi_ioaccel_raid_map() function no longer occurs. (BZ#1335411)

* In a previous code update one extra spin_lock operation was left untouched. Consequently, a deadlock could occur when looping through cache pages. With this update, the extra lock operation has been removed from the source code and the deadlock no longer occurs in the described situation. (BZ#1327073)

ID	Name	Product	Family	Severity
245907	Linux Distros Unpatched Vulnerability : CVE-2016-3707	Nessus	Misc.	high
91872	RHEL 6 : MRG (RHSA-2016:1341)	Nessus	Red Hat Local Security Checks	high
91805	RHEL 7 : kernel-rt (RHSA-2016:1301)	Nessus	Red Hat Local Security Checks	high

Detections

Analytics

CVE-2016-3707

high

Tenable Plugins

high

high

high