Race condition in the kernel in Red Hat Enterprise Linux 7, kernel-rt and Red Hat Enterprise MRG 2, when the nfnetlink_log module is loaded, allows local users to cause a denial of service (panic) by creating netlink sockets.

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

  - Race condition in the kernel in Red Hat Enterprise Linux 7, kernel-rt and Red Hat Enterprise MRG 2, when     the nfnetlink_log module is loaded, allows local users to cause a denial of service (panic) by creating     netlink sockets. (CVE-2015-7553)

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

Updated kernel packages that fix multiple security issues, address several hundred bugs, and add numerous enhancements are now available as part of the ongoing support and maintenance of Red Hat Enterprise Linux version 7. This is the second regular update.

Red Hat Product Security has rated this update as having Important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

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

* A flaw was found in the way the Linux kernel's file system implementation handled rename operations in which the source was inside and the destination was outside of a bind mount. A privileged user inside a container could use this flaw to escape the bind mount and, potentially, escalate their privileges on the system.
(CVE-2015-2925, Important)

* A race condition flaw was found in the way the Linux kernel's IPC subsystem initialized certain fields in an IPC object structure that were later used for permission checking before inserting the object into a globally visible list. A local, unprivileged user could potentially use this flaw to elevate their privileges on the system.
(CVE-2015-7613, Important)

* It was found that reporting emulation failures to user space could lead to either a local (CVE-2014-7842) or a L2->L1 (CVE-2010-5313) denial of service. In the case of a local denial of service, an attacker must have access to the MMIO area or be able to access an I/O port. (CVE-2010-5313, CVE-2014-7842, Moderate)

* A flaw was found in the way the Linux kernel's KVM subsystem handled non-canonical addresses when emulating instructions that change the RIP (for example, branches or calls). A guest user with access to an I/O or MMIO region could use this flaw to crash the guest.
(CVE-2014-3647, Moderate)

* It was found that the Linux kernel memory resource controller's (memcg) handling of OOM (out of memory) conditions could lead to deadlocks. An attacker could use this flaw to lock up the system.
(CVE-2014-8171, Moderate)

* A race condition flaw was found between the chown and execve system calls. A local, unprivileged user could potentially use this flaw to escalate their privileges on the system. (CVE-2015-3339, Moderate)

* A flaw was discovered in the way the Linux kernel's TTY subsystem handled the tty shutdown phase. A local, unprivileged user could use this flaw to cause a denial of service on the system. (CVE-2015-4170, Moderate)

* A NULL pointer dereference flaw was found in the SCTP implementation. A local user could use this flaw to cause a denial of service on the system by triggering a kernel panic when creating multiple sockets in parallel while the system did not have the SCTP module loaded. (CVE-2015-5283, Moderate)

* A flaw was found in the way the Linux kernel's perf subsystem retrieved userlevel stack traces on PowerPC systems. A local, unprivileged user could use this flaw to cause a denial of service on the system. (CVE-2015-6526, Moderate)

* A flaw was found in the way the Linux kernel's Crypto subsystem handled automatic loading of kernel modules. A local user could use this flaw to load any installed kernel module, and thus increase the attack surface of the running kernel. (CVE-2013-7421, CVE-2014-9644, Low)

* An information leak flaw was found in the way the Linux kernel changed certain segment registers and thread-local storage (TLS) during a context switch. A local, unprivileged user could use this flaw to leak the user space TLS base address of an arbitrary process.
(CVE-2014-9419, Low)

* It was found that the Linux kernel KVM subsystem's sysenter instruction emulation was not sufficient. An unprivileged guest user could use this flaw to escalate their privileges by tricking the hypervisor to emulate a SYSENTER instruction in 16-bit mode, if the guest OS did not initialize the SYSENTER model-specific registers (MSRs). Note: Certified guest operating systems for Red Hat Enterprise Linux with KVM do initialize the SYSENTER MSRs and are thus not vulnerable to this issue when running on a KVM hypervisor.
(CVE-2015-0239, Low)

* A flaw was found in the way the Linux kernel handled the securelevel functionality after performing a kexec operation. A local attacker could use this flaw to bypass the security mechanism of the securelevel/secureboot combination. (CVE-2015-7837, Low)

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2015:2152 advisory.

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

    * A flaw was found in the way the Linux kernel's file system implementation     handled rename operations in which the source was inside and the     destination was outside of a bind mount. A privileged user inside a     container could use this flaw to escape the bind mount and, potentially,     escalate their privileges on the system. (CVE-2015-2925, Important)

    * A race condition flaw was found in the way the Linux kernel's IPC     subsystem initialized certain fields in an IPC object structure that were     later used for permission checking before inserting the object into a     globally visible list. A local, unprivileged user could potentially use     this flaw to elevate their privileges on the system. (CVE-2015-7613,     Important)

    * It was found that reporting emulation failures to user space could lead     to either a local (CVE-2014-7842) or a L2->L1 (CVE-2010-5313) denial of     service. In the case of a local denial of service, an attacker must have     access to the MMIO area or be able to access an I/O port. (CVE-2010-5313,     CVE-2014-7842, Moderate)

    * A flaw was found in the way the Linux kernel's KVM subsystem handled     non-canonical addresses when emulating instructions that change the RIP     (for example, branches or calls). A guest user with access to an I/O or     MMIO region could use this flaw to crash the guest. (CVE-2014-3647,     Moderate)

    * It was found that the Linux kernel memory resource controller's (memcg)     handling of OOM (out of memory) conditions could lead to deadlocks.
    An attacker could use this flaw to lock up the system. (CVE-2014-8171,     Moderate)

    * A race condition flaw was found between the chown and execve system     calls. A local, unprivileged user could potentially use this flaw to     escalate their privileges on the system. (CVE-2015-3339, Moderate)

    * A flaw was discovered in the way the Linux kernel's TTY subsystem handled     the tty shutdown phase. A local, unprivileged user could use this flaw to     cause a denial of service on the system. (CVE-2015-4170, Moderate)

    * A NULL pointer dereference flaw was found in the SCTP implementation.
    A local user could use this flaw to cause a denial of service on the system     by triggering a kernel panic when creating multiple sockets in parallel     while the system did not have the SCTP module loaded. (CVE-2015-5283,     Moderate)

    * A flaw was found in the way the Linux kernel's perf subsystem retrieved     userlevel stack traces on PowerPC systems. A local, unprivileged user could     use this flaw to cause a denial of service on the system. (CVE-2015-6526,     Moderate)

    * A flaw was found in the way the Linux kernel's Crypto subsystem handled     automatic loading of kernel modules. A local user could use this flaw to     load any installed kernel module, and thus increase the attack surface of     the running kernel. (CVE-2013-7421, CVE-2014-9644, Low)

    * An information leak flaw was found in the way the Linux kernel changed     certain segment registers and thread-local storage (TLS) during a context     switch. A local, unprivileged user could use this flaw to leak the user     space TLS base address of an arbitrary process. (CVE-2014-9419, Low)

    * It was found that the Linux kernel KVM subsystem's sysenter instruction     emulation was not sufficient. An unprivileged guest user could use this     flaw to escalate their privileges by tricking the hypervisor to emulate a     SYSENTER instruction in 16-bit mode, if the guest OS did not initialize the     SYSENTER model-specific registers (MSRs). Note: Certified guest operating     systems for Red Hat Enterprise Linux with KVM do initialize the SYSENTER     MSRs and are thus not vulnerable to this issue when running on a KVM     hypervisor. (CVE-2015-0239, Low)

    * A flaw was found in the way the Linux kernel handled the securelevel     functionality after performing a kexec operation. A local attacker could     use this flaw to bypass the security mechanism of the     securelevel/secureboot combination. (CVE-2015-7837, Low)

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
219040	Linux Distros Unpatched Vulnerability : CVE-2015-7553	Nessus	Misc.	medium
87135	CentOS 7 : kernel (CESA-2015:2152)	Nessus	CentOS Local Security Checks	high
86972	RHEL 7 : kernel (RHSA-2015:2152)	Nessus	Red Hat Local Security Checks	high

Detections

Analytics

CVE-2015-7553

medium

Tenable Plugins

medium

high

high