An update for kernel is now available for Red Hat Enterprise Linux 6.

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.

[Updated 16th August 2018] The original errata text was missing reference to CVE-2018-5390 fix. We have updated the errata text to correct this issue. No changes have been made to the packages.

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

Security Fix(es) :

* Modern operating systems implement virtualization of physical memory to efficiently use available system resources and provide inter-domain protection through access control and isolation. The L1TF issue was found in the way the x86 microprocessor designs have implemented speculative execution of instructions (a commonly used performance optimisation) in combination with handling of page-faults caused by terminated virtual to physical address resolving process. As a result, an unprivileged attacker could use this flaw to read privileged memory of the kernel or other processes and/or cross guest/host boundaries to read host memory by conducting targeted cache side-channel attacks.
(CVE-2018-3620, CVE-2018-3646)

* An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of instructions past bounds check. The flaw relies on the presence of a precisely-defined instruction sequence in the privileged code and the fact that memory writes occur to an address which depends on the untrusted value. Such writes cause an update into the microprocessor's data cache even for speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to influence speculative execution and/or read privileged memory by conducting targeted cache side-channel attacks.
(CVE-2018-3693)

* A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system. Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port, thus the attacks cannot be performed using spoofed IP addresses.
(CVE-2018-5390)

* kernel: kvm: vmx: host GDT limit corruption (CVE-2018-10901)

* kernel: Use-after-free in snd_pcm_info function in ALSA subsystem potentially leads to privilege escalation (CVE-2017-0861)

* kernel: Use-after-free in snd_seq_ioctl_create_port() (CVE-2017-15265)

* kernel: race condition in snd_seq_write() may lead to UAF or OOB-access (CVE-2018-7566)

* kernel: Race condition in sound system can lead to denial of service (CVE-2018-1000004)

For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section.

Red Hat would like to thank Intel OSSIRT (Intel.com) for reporting CVE-2018-3620 and CVE-2018-3646; Vladimir Kiriansky (MIT) and Carl Waldspurger (Carl Waldspurger Consulting) for reporting CVE-2018-3693;
Juha-Matti Tilli (Aalto University, Department of Communications and Networking and Nokia Bell Labs) for reporting CVE-2018-5390; and Vegard Nossum (Oracle Corporation) for reporting CVE-2018-10901.

Bug Fix(es) :

* The Least recently used (LRU) operations are batched by caching pages in per-cpu page vectors to prevent contention of the heavily used lru_lock spinlock. The page vectors can hold even the compound pages. Previously, the page vectors were cleared only if they were full. Subsequently, the amount of memory held in page vectors, which is not reclaimable, was sometimes too high. Consequently the page reclamation started the Out of Memory (OOM) killing processes. With this update, the underlying source code has been fixed to clear LRU page vectors each time when a compound page is added to them. As a result, OOM killing processes due to high amounts of memory held in page vectors no longer occur. (BZ#1575819)

Security Fix(es) :

  - Modern operating systems implement virtualization of     physical memory to efficiently use available system     resources and provide inter-domain protection through     access control and isolation. The L1TF issue was found     in the way the x86 microprocessor designs have     implemented speculative execution of instructions (a     commonly used performance optimisation) in combination     with handling of page-faults caused by terminated     virtual to physical address resolving process. As a     result, an unprivileged attacker could use this flaw to     read privileged memory of the kernel or other processes     and/or cross guest/host boundaries to read host memory     by conducting targeted cache side-channel attacks.
    (CVE-2018-3620, CVE-2018-3646)

  - An industry-wide issue was found in the way many modern     microprocessor designs have implemented speculative     execution of instructions past bounds check. The flaw     relies on the presence of a precisely-defined     instruction sequence in the privileged code and the fact     that memory writes occur to an address which depends on     the untrusted value. Such writes cause an update into     the microprocessor's data cache even for speculatively     executed instructions that never actually commit     (retire). As a result, an unprivileged attacker could     use this flaw to influence speculative execution and/or     read privileged memory by conducting targeted cache     side- channel attacks. (CVE-2018-3693)

  - kernel: kvm: vmx: host GDT limit corruption     (CVE-2018-10901)

  - kernel: Use-after-free in snd_pcm_info function in ALSA     subsystem potentially leads to privilege escalation     (CVE-2017-0861)

  - kernel: Use-after-free in snd_seq_ioctl_create_port()     (CVE-2017-15265)

  - kernel: race condition in snd_seq_write() may lead to     UAF or OOB-access (CVE-2018-7566)

  - kernel: Race condition in sound system can lead to     denial of service (CVE-2018-1000004)

Bug Fix(es) :

  - The Least recently used (LRU) operations are batched by     caching pages in per-cpu page vectors to prevent     contention of the heavily used lru_lock spinlock. The     page vectors can hold even the compound pages.
    Previously, the page vectors were cleared only if they     were full. Subsequently, the amount of memory held in     page vectors, which is not reclaimable, was sometimes     too high. Consequently the page reclamation started the     Out of Memory (OOM) killing processes. With this update,     the underlying source code has been fixed to clear LRU     page vectors each time when a compound page is added to     them. As a result, OOM killing processes due to high     amounts of memory held in page vectors no longer occur.

Race condition in the store_int_with_restart() function in cpu/mcheck/mce.c :

A race condition in the store_int_with_restart() function in arch/x86/kernel/cpu/mcheck/mce.c in the Linux kernel allows local users to cause a denial of service (panic) by leveraging root access to write to the check_interval file in a /sys/devices/system/machinecheck/machinecheck<cpu number> directory.
(CVE-2018-7995)

Out-of-bounds write via userland offsets in ebt_entry struct in netfilter/ebtables.c :

A flaw was found in the Linux kernel's implementation of 32-bit syscall interface for bridging. This allowed a privileged user to arbitrarily write to a limited range of kernel memory. (CVE-2018-1068)

A flaw was found in the Linux kernel's skcipher component, which affects the skcipher_recvmsg function. Attackers using a specific input can lead to a privilege escalation.(CVE-2017-13215)

The do_get_mempolicy() function in mm/mempolicy.c in the Linux kernel allows local users to hit a use-after-free bug via crafted system calls and thus cause a denial of service (DoS) or possibly have unspecified other impact. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.(CVE-2018-10675)

A flaw was found in Linux kernel's KVM virtualization subsystem. The VMX code does not restore the GDT.LIMIT to the previous host value, but instead sets it to 64KB. With a corrupted GDT limit a host's userspace code has an ability to place malicious entries in the GDT, particularly to the per-cpu variables. An attacker can use this to escalate their privileges.(CVE-2018-10901)

The remote Oracle Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2018-2390 advisory.

    - [kernel] cpu/hotplug: Enable 'nosmt' as late as possible (Frantisek Hrbata) [1593376] {CVE-2018-3620}
    - [x86] x86/mm: Simplify p[g4um]d_page() macros (Josh Poimboeuf) [1593376] {CVE-2018-3620}
    - [x86] x86/mm: Fix regression with huge pages on PAE (Josh Poimboeuf) [1593376] {CVE-2018-3620}
    - [x86] x86/asm: Fix pud/pmd interfaces to handle large PAT bit (Josh Poimboeuf) [1593376] {CVE-2018-3620}
    - [x86] x86/asm: Add pud/pmd mask interfaces to handle large PAT bit (Josh Poimboeuf) [1593376]     {CVE-2018-3620}
    - [x86] x86/asm: Move PUD_PAGE macros to page_types.h (Josh Poimboeuf) [1593376] {CVE-2018-3620}
    - [net] tcp: detect malicious patterns in tcp_collapse_ofo_queue() (Florian Westphal) [1611376]     {CVE-2018-5390}
    - [net] tcp: avoid collapses in tcp_prune_queue() if possible (Florian Westphal) [1611376] {CVE-2018-5390}
    - [net] tcp: free batches of packets in tcp_prune_ofo_queue() (Florian Westphal) [1611376] {CVE-2018-5390}
    - [net] add rb_to_skb() and other rb tree helpers (Florian Westphal) [1611376] {CVE-2018-5390}
    - [net] tcp: fix a stale ooo_last_skb after a replace (Florian Westphal) [1611376] {CVE-2018-5390}
    - [net] tcp: use an RB tree for ooo receive queue (Florian Westphal) [1611376] {CVE-2018-5390}
    - [net] add rbnode to struct sk_buff (Florian Westphal) [1611376] {CVE-2018-5390}
    - [net] tcp: refine tcp_prune_ofo_queue() to not drop all packets (Florian Westphal) [1611376]     {CVE-2018-5390}
    - [x86] syscall: Fix regression when using the last syscall (process_vm_writev) (Lauro Ramos Venancio)     [1589032] {CVE-2018-3693}
    - [x86] syscall: Fix regression on strace and stap (Lauro Ramos Venancio) [1589032] {CVE-2018-3693}
    - [kvm] VMX: Fix host GDT.LIMIT corruption (CVE-2018-10301) (Paolo Bonzini) [1601851] {CVE-2018-10901}
    - [x86] Initialize __max_smt_threads to 1 (Waiman Long) [1593376] {CVE-2018-3620}
    - [kernel] cpu/hotplug: detect SMT disabled by BIOS (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] topology: Add topology_max_smt_threads() (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] speculation/l1tf: Fix incorrect error return code in vm_insert_pfn() (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] KVM/VMX: Initialize the vmx_l1d_flush_pages' content (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] kvm: Don't flush L1D cache if VMENTER_L1D_FLUSH_NEVER (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] kvm: Take out the unused nosmt module parameter (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] mm/dump_pagetables: Add a check_l1tf debugfs file (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] l1tf: protect _PAGE_FILE PTEs against speculation for 32-bit PAE (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] speculation/l1tf: Protect swap entries aganst L1TF for 32-bit PAE (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] cpu: Make flush_l1d visible in /proc/cpuinfo (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] l1tf: protect _PAGE_FILE PTEs against speculation (Waiman Long) [1593376] {CVE-2018-3620}
    - [Documentation] Add section about CPU vulnerabilities (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] bugs, kvm: Introduce boot-time control of L1TF mitigations (Waiman Long) [1593376] {CVE-2018-3620}
    - [kernel] cpu/hotplug: Set CPU_SMT_NOT_SUPPORTED early (Waiman Long) [1593376] {CVE-2018-3620}
    - [kernel] cpu/hotplug: Expose SMT control init function (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] kvm: Allow runtime control of L1D flush (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] kvm: Serialize L1D flush parameter setter (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] kvm: Move l1tf setup function (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] l1tf: Handle EPT disabled state proper (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] kvm: Drop L1TF MSR list approach (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] litf: Introduce vmx status variable (Waiman Long) [1593376] {CVE-2018-3620}
    - [kernel] cpu/hotplug: Online siblings when SMT control is turned on (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] KVM/VMX: Use MSR save list for IA32_FLUSH_CMD if required (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] KVM/VMX: Separate the VMX AUTOLOAD guest/host number accounting (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] KVM/VMX: Add find_msr() helper function (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] KVM/VMX: Split the VMX MSR LOAD structures to have an host/guest numbers (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] KVM/VMX: Add L1D flush logic (Waiman Long) [1593376] {CVE-2018-3620}
    - [kvm] VMX: Make indirect call speculation safe (Waiman Long) [1593376] {CVE-2018-3620}
    - [kvm] VMX: Enable acknowledge interupt on vmexit (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] KVM/VMX: Add L1D MSR based flush (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] KVM/VMX: Add L1D flush algorithm (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] KVM/VMX: Add module argument for L1TF mitigation (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] KVM: Warn user if KVM is loaded SMT and L1TF CPU bug being present (Waiman Long) [1593376]     {CVE-2018-3620}
    - [kvm] x86: Introducing kvm_x86_ops VM init/destroy hooks (Waiman Long) [1593376] {CVE-2018-3620}
    - [kernel] cpu/hotplug: Boot HT siblings at least once (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] Revert 'x86/apic: Ignore secondary threads if nosmt=force' (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] speculation/l1tf: Fix up pte->pfn conversion for PAE (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] CPU/AMD: Move TOPOEXT reenablement before reading smp_num_siblings (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] cpufeatures: Add detection of L1D cache flush support. (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] speculation/l1tf: Extend 64bit swap file size limit (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] apic: Ignore secondary threads if nosmt=force (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] cpu/AMD: Evaluate smp_num_siblings early (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] CPU/AMD: Do not check CPUID max ext level before parsing SMP info (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] cpu/intel: Evaluate smp_num_siblings early (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] cpu/topology: Provide detect_extended_topology_early() (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] cpu/common: Provide detect_ht_early() (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] cpu/AMD: Remove the pointless detect_ht() call (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] cpu: Remove the pointless CPU printout (Waiman Long) [1593376] {CVE-2018-3620}
    - [kernel] cpu/hotplug: Provide knobs to control SMT (Waiman Long) [1593376] {CVE-2018-3620}
    - [kernel] cpu/hotplug: Split do_cpu_down() (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] topology: Provide topology_smt_supported() (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] smp: Provide topology_is_primary_thread() (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] bugs: Move the l1tf function and define pr_fmt properly (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] speculation/l1tf: Limit swap file size to MAX_PA/2 (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] speculation/l1tf: Add sysfs reporting for l1tf (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] speculation/l1tf: Protect PROT_NONE PTEs against speculation (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] speculation/l1tf: Protect swap entries against L1TF (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] speculation/l1tf: Change order of offset/type in swap entry (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] speculation/l1tf: Increase 32bit PAE __PHYSICAL_PAGE_SHIFT (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] cpu: Fix incorrect vulnerabilities files function prototypes (Waiman Long) [1593376]     {CVE-2018-3620}
    - [x86] bugs: Export the internal __cpu_bugs variable (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] spec_ctrl: sync with upstream cpu_set_bug_bits() (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] intel-family.h: Add GEMINI_LAKE SOC (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] mm: Fix swap entry comment and macro (Waiman Long) [1593376] {CVE-2018-3620}
    - [x86] mm: Move swap offset/type up in PTE to work around erratum (Waiman Long) [1593376] {CVE-2018-3620}
    - [sound] alsa: pcm: prevent UAF in snd_pcm_info (CVE-2017-0861) (Jaroslav Kysela) [1565188]     {CVE-2017-0861}
    - [sound] alsa: seq: Fix racy pool initializations (Jaroslav Kysela) [1550176] {CVE-2018-7566}
    - [sound] alsa: seq: Fix use-after-free at creating a port (Jaroslav Kysela) [1503383] {CVE-2017-15265}
    - [sound] alsa: seq: Make ioctls race-free (Jaroslav Kysela) [1537452] {CVE-2018-1000004}
    - [usb] acm: fix the computation of the number of data bits (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [misc] spectre: fix gadgets found by smatch scanner, part 2 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [x86] kvm/vmx: Remove barrier_nospec() in slot_largepage_idx() (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [kvm] Remove memory alias support (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [misc] spectre: fix gadgets found by smatch scanner (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [sound] alsa: rme9652: Hardening for potential Spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [sound] alsa: opl3: Hardening for potential Spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [sound] alsa: hda: Hardening for potential Spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [sound] alsa: seq: oss: Hardening for potential Spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [sound] alsa: seq: oss: Fix unbalanced use lock for synth MIDI device (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [net] atm: Fix potential Spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [kernel] posix-timers: Protect posix clock array access against speculation (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [kernel] sys.c: fix potential Spectre v1 issue (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [kernel] sched/autogroup: Fix possible Spectre-v1 indexing for sched_prio_to_weight[] (Josh Poimboeuf)     [1589032] {CVE-2018-3693}
    - [kernel] perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[] (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [ipc] sysvipc/sem: mitigate semnum index against spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [sound] alsa: control: Hardening for potential Spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [media] dvb_ca_en50221: prevent using slot_info for Spectre attacs (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - media] dvb_ca_en50221: sanity check slot number from userspace (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [atm] zatm: Fix potential Spectre v1 (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [x86] perf: Fix possible Spectre-v1 indexing for x86_pmu::event_map() (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [x86] perf: Fix possible Spectre-v1 indexing for hw_perf_event cache_* (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [net] nl80211: Sanitize array index in parse_txq_params (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [include] vfs, fdtable: Prevent bounds-check bypass via speculative execution (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [x86] syscall: Sanitize syscall table de-references under speculation (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [powerpc] Use barrier_nospec in copy_from_user() (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [include] nospec: Introduce barrier_nospec for other arches (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [x86] Introduce barrier_nospec (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [x86] spectre_v1: Disable compiler optimizations over array_index_mask_nospec() (Josh Poimboeuf)     [1589032] {CVE-2018-3693}
    - [x86] Implement array_index_mask_nospec (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [documentation] Document array_index_nospec (Josh Poimboeuf) [1589032] {CVE-2018-3693}     dependency (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [include] nospec: Allow index argument to have const-qualified type (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [include] nospec: Kill array_index_nospec_mask_check() (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [include] nospec: Move array_index_nospec() parameter checking into separate macro (Josh Poimboeuf)     [1589032] {CVE-2018-3693}
    - [include] array_index_nospec: Sanitize speculative array de-references (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [x86] get_user: Use pointer masking to limit speculation (Josh Poimboeuf) [1589032] {CVE-2018-3693}
    - [x86] uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [x86] Introduce __uaccess_begin_nospec() and uaccess_try_nospec (Josh Poimboeuf) [1589032]     {CVE-2018-3693}
    - [x86] reorganize SMAP handling in user space accesses (Josh Poimboeuf) [1589032] {CVE-2018-3693}

Tenable has extracted the preceding description block directly from the Oracle 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.

The version of F5 Networks BIG-IP installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the K07721343 advisory.

  - A flaw was found in Linux kernel's KVM virtualization subsystem. The VMX code does not restore the     GDT.LIMIT to the previous host value, but instead sets it to 64KB. With a corrupted GDT limit a host's     userspace code has an ability to place malicious entries in the GDT, particularly to the per-cpu     variables. An attacker can use this to escalate their privileges. (CVE-2018-10901)

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

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

  - A flaw was found in Linux kernel's KVM virtualization subsystem. The VMX code does not restore the     GDT.LIMIT to the previous host value, but instead sets it to 64KB. With a corrupted GDT limit a host's     userspace code has an ability to place malicious entries in the GDT, particularly to the per-cpu     variables. An attacker can use this to escalate their privileges. (CVE-2018-10901)

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

ID	名称	产品	系列	发布时间	最近更新时间	严重程度
111704	CentOS 6 : kernel (CESA-2018:2390) (Foreshadow)	Nessus	CentOS Local Security Checks	2018/8/15	2024/8/21	high
111777	Scientific Linux Security Update : kernel on SL6.x i386/x86_64 (20180814) (Foreshadow)	Nessus	Scientific Linux Local Security Checks	2018/8/16	2024/8/21	high
109177	Amazon Linux 2 : kernel (ALAS-2018-994)	Nessus	Amazon Linux Local Security Checks	2018/4/20	2024/10/30	high
111724	Oracle Linux 6 : kernel (ELSA-2018-2390)	Nessus	Oracle Linux Local Security Checks	2018/8/15	2026/2/9	high
184229	F5 Networks BIG-IP : Linux kernel vulnerability (K07721343)	Nessus	F5 Networks Local Security Checks	2023/11/2	2024/5/7	high
244636	Linux Distros Unpatched Vulnerability : CVE-2018-10901	Nessus	Misc.	2025/8/7	2025/8/7	high

检测

插件搜索

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