The collect_mounts function in fs/namespace.c in the Linux kernel before 4.0.5 does not properly consider that it may execute after a path has been unmounted, which allows local users to cause a denial of service (system crash) by leveraging user-namespace root access for an MNT_DETACH umount2 system call.

The remote Redhat Enterprise Linux 7 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - kernel: out of bounds read in drivers/media/usb/dvb-usb/technisat-usb2.c (CVE-2019-15505)

  - kernel: buffer-overflow hardening in WiFi beacon validation code. (CVE-2019-16746)

  - block/scsi_ioctl.c in the Linux kernel through 3.8 does not properly consider the SCSI device class during     authorization of SCSI commands, which allows local users to bypass intended access restrictions via an     SG_IO ioctl call that leverages overlapping opcodes. (CVE-2012-4542)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

According to the versions of the kernel packages installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities :

  - The ims_pcu_get_cdc_union_desc function in     drivers/input/misc/ims-pcu.c in the Linux kernel,     through 4.13.11, allows local users to cause a denial     of service (ims_pcu_parse_cdc_data out-of-bounds read     and system crash) or possibly have unspecified other     impact via a crafted USB device.(CVE-2017-16645i1/4%0

  - It was found that due to excessive files_lock locking,     a soft lockup could be triggered in the Linux kernel     when performing asynchronous I/O operations. A local,     unprivileged user could use this flaw to crash the     system.(CVE-2014-8172i1/4%0

  - A flaw was discovered in the kernel's collect_mounts     function. If the kernel's audit subsystem called     collect_mounts to audit an unmounted path, it could     panic the system. With this flaw, an unprivileged user     could call umount(MNT_DETACH) to launch a     denial-of-service attack.(CVE-2015-4177i1/4%0

  - A flaw was found in the way the Linux kernel's floppy     driver handled user space provided data in certain     error code paths while processing FDRAWCMD IOCTL     commands. A local user with write access to /dev/fdX     could use this flaw to free (using the kfree()     function) arbitrary kernel memory. (CVE-2014-1737,     Important) was found that the Linux kernel's floppy     driver leaked internal kernel memory addresses to user     space during the processing of the FDRAWCMD IOCTL     command. A local user with write access to /dev/fdX     could use this flaw to obtain information about the     kernel heap arrangement. (CVE-2014-1738, Low)Note: A     local user with write access to /dev/fdX could use     these two flaws (CVE-2014-1737 in combination with     CVE-2014-1738) to escalate their privileges on the     system.(CVE-2014-1738i1/4%0

  - A reference counter leak in Linux kernel in     ipxitf_ioctl function was found which results in a use     after free vulnerability that's triggerable from     unprivileged userspace when IPX interface is     configured.(CVE-2017-7487i1/4%0

  - The x25_recvmsg function in net/x25/af_x25.c in the     Linux kernel before 3.12.4 updates a certain length     value without ensuring that an associated data     structure has been initialized, which allows local     users to obtain sensitive information from kernel     memory via a (1) recvfrom, (2) recvmmsg, or (3) recvmsg     system call.(CVE-2013-7271i1/4%0

  - An inode data validation error was found in Linux     kernels built with UDF file system (CONFIG_UDF_FS)     support. An attacker able to mount a     corrupted/malicious UDF file system image could cause     the kernel to crash.(CVE-2015-4167i1/4%0

  - Double free vulnerability in the ioctx_alloc function     in fs/aio.c in the Linux kernel before 3.12.4 allows     local users to cause a denial of service (system crash)     or possibly have unspecified other impact via vectors     involving an error condition in the aio_setup_ring     function.(CVE-2013-7348i1/4%0

  - A flaw was found in the Linux kernel's implementation     of setsockopt for the SO_{SND|RCV}BUFFORCE setsockopt()     system call. Users with non-namespace CAP_NET_ADMIN are     able to trigger this call and create a situation in     which the sockets sendbuff data size could be negative.
    This could adversely affect memory allocations and     create situations where the system could crash or cause     memory corruption.(CVE-2016-9793i1/4%0

  - Use-after-free vulnerability in the     ffs_user_copy_worker function in     drivers/usb/gadget/function/f_fs.c in the Linux kernel     before 4.5.3 allows local users to gain privileges by     accessing an I/O data structure after a certain     callback call. Due to the nature of the flaw, privilege     escalation cannot be fully ruled out, although we     believe it is unlikely.(CVE-2016-7912i1/4%0

  - A flaw was found in the way the get_dumpable() function     return value was interpreted in the ptrace subsystem of     the Linux kernel. When 'fs.suid_dumpable' was set to 2,     a local, unprivileged local user could use this flaw to     bypass intended ptrace restrictions and obtain     potentially sensitive information.(CVE-2013-2929i1/4%0

  - A DoS flaw was found for a Linux kernel built for the     x86 architecture which had the KVM virtualization     support(CONFIG_KVM) enabled. The kernel would be     vulnerable to a NULL pointer dereference flaw in Linux     kernel's kvm_apic_has_events() function while doing an     ioctl. An unprivileged user able to access the     '/dev/kvm' device could use this flaw to crash the     system kernel.(CVE-2015-4692i1/4%0

  - The intr function in sound/oss/msnd_pinnacle.c in the     Linux kernel through 4.11.7 allows local users to cause     a denial of service (over-boundary access) or possibly     have unspecified other impact by changing the value of     a message queue head pointer between two kernel reads     of that value, aka a 'double fetch'     vulnerability.(CVE-2017-9986i1/4%0

  - sound/soc/msm/qdsp6v2/msm-audio-effects-q6-v2.c in the     MSM QDSP6 audio driver for the Linux kernel 3.x, as     used in Qualcomm Innovation Center (QuIC) Android     contributions for MSM devices and other products,     allows attackers to cause a denial of service (buffer     over-read) or possibly have unspecified other impact     via a crafted application that makes an ioctl call     specifying many commands.(CVE-2016-2064i1/4%0

  - The digi_port_init function in     drivers/usb/serial/digi_acceleport.c in the Linux     kernel before 4.5.1 allows physically proximate     attackers to cause a denial of service (NULL pointer     dereference and system crash) via a crafted endpoints     value in a USB device descriptor.(CVE-2016-3140i1/4%0

  - In the Linux kernel through 4.14.13, the     rds_cmsg_atomic function in net/rds/rdma.c mishandles     cases where page pinning fails or an invalid address is     supplied, leading to an rds_atomic_free_op NULL pointer     dereference.(CVE-2018-5333i1/4%0

  - Multiple buffer underflows in the XFS implementation in     the Linux kernel through 3.12.1 allow local users to     cause a denial of service (memory corruption) or     possibly have unspecified other impact by leveraging     the CAP_SYS_ADMIN capability for a (1)     XFS_IOC_ATTRLIST_BY_HANDLE or (2)     XFS_IOC_ATTRLIST_BY_HANDLE_32 ioctl call with a crafted     length value, related to the xfs_attrlist_by_handle     function in fs/xfs/xfs_ioctl.c and the     xfs_compat_attrlist_by_handle function in     fs/xfs/xfs_ioctl32.c.(CVE-2013-6382i1/4%0

  - In the Linux kernel through 5.0.2, the function     inotify_update_existing_watch() in     fs/notify/inotify/inotify_user.c neglects to call     fsnotify_put_mark() with IN_MASK_CREATE after     fsnotify_find_mark(), which will cause a memory leak     (aka refcount leak). Finally, this will cause a denial     of service.(CVE-2019-9857i1/4%0

  - It was found that stacking a file system over procfs in     the Linux kernel could lead to a kernel stack overflow     due to deep nesting, as demonstrated by mounting     ecryptfs over procfs and creating a recursion by     mapping /proc/environ. An unprivileged, local user     could potentially use this flaw to escalate their     privileges on the system.(CVE-2016-1583i1/4%0

  - A heap-based buffer overflow vulnerability was found in     the Linux kernel's hiddev driver. This flaw could allow     a local attacker to corrupt kernel memory, possible     privilege escalation or crashing the     system.(CVE-2016-5829i1/4%0

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the kernel packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

  - It was found that the Linux kernel's implementation of     vectored pipe read and write functionality did not take     into account the I/O vectors that were already     processed when retrying after a failed atomic access     operation, potentially resulting in memory corruption     due to an I/O vector array overrun. A local,     unprivileged user could use this flaw to crash the     system or, potentially, escalate their privileges on     the system.(CVE-2015-1805)

  - net/llc/sysctl_net_llc.c in the Linux kernel before     3.19 uses an incorrect data type in a sysctl table,     which allows local users to obtain potentially     sensitive information from kernel memory or possibly     have unspecified other impact by accessing a sysctl     entry.(CVE-2015-2041)

  - net/rds/sysctl.c in the Linux kernel before 3.19 uses     an incorrect data type in a sysctl table, which allows     local users to obtain potentially sensitive information     from kernel memory or possibly have unspecified other     impact by accessing a sysctl entry.(CVE-2015-2042)

  - Xen 3.3.x through 4.5.x and the Linux kernel through     3.19.1 do not properly restrict access to PCI command     registers, which might allow local guest OS users to     cause a denial of service (non-maskable interrupt and     host crash) by disabling the (1) memory or (2) I/O     decoding for a PCI Express device and then accessing     the device, which triggers an Unsupported Request (UR)     response.(CVE-2015-2150)

  - A stack-based buffer overflow flaw was found in the     Linux kernel's early load microcode functionality. On a     system with UEFI Secure Boot enabled, a local,     privileged user could use this flaw to increase their     privileges to the kernel (ring0) level, bypassing     intended restrictions in place.(CVE-2015-2666)

  - The xsave/xrstor implementation in     arch/x86/include/asm/xsave.h in the Linux kernel before     3.19.2 creates certain .altinstr_replacement pointers     and consequently does not provide any protection     against instruction faulting, which allows local users     to cause a denial of service (panic) by triggering a     fault, as demonstrated by an unaligned memory operand     or a non-canonical address memory     operand.(CVE-2015-2672)

  - A flaw was found in the way the Linux kernel's 32-bit     emulation implementation handled forking or closing of     a task with an 'int80' entry. A local user could     potentially use this flaw to escalate their privileges     on the system.(CVE-2015-2830)

  - It was found that the Linux kernel's TCP/IP protocol     suite implementation for IPv6 allowed the Hop Limit     value to be set to a smaller value than the default     one. An attacker on a local network could use this flaw     to prevent systems on that network from sending or     receiving network packets.(CVE-2015-2922)

  - 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)

  - A race condition flaw was found in the way the Linux     kernel's SCTP implementation handled Address     Configuration lists when performing Address     Configuration Change (ASCONF). A local attacker could     use this flaw to crash the system via a race condition     triggered by setting certain ASCONF options on a     socket.(CVE-2015-3212)

  - mm/memory.c in the Linux kernel before 4.1.4 mishandles     anonymous pages, which allows local users to gain     privileges or cause a denial of service (page tainting)     via a crafted application that triggers writing to page     zero.(CVE-2015-3288)

  - A flaw was found in the way the Linux kernel's nested     NMI handler and espfix64 functionalities interacted     during NMI processing. A local, unprivileged user could     use this flaw to crash the system or, potentially,     escalate their privileges on the system.(CVE-2015-3290)

  - It was found that if a Non-Maskable Interrupt (NMI)     occurred immediately after a SYSCALL call or before a     SYSRET call with the user RSP pointing to the NMI IST     stack, the kernel could skip that NMI.(CVE-2015-3291)

  - A buffer overflow flaw was found in the way the Linux     kernel's Intel AES-NI instructions optimized version of     the RFC4106 GCM mode decryption functionality handled     fragmented packets. A remote attacker could use this     flaw to crash, or potentially escalate their privileges     on, a system over a connection with an active AES-GCM     mode IPSec security association.(CVE-2015-3331)

  - A race condition flaw was found between the chown and     execve system calls. When changing the owner of a     setuid user binary to root, the race condition could     momentarily make the binary setuid root. A local,     unprivileged user could potentially use this flaw to     escalate their privileges on the system.(CVE-2015-3339)

  - It was found that the Linux kernel's ping socket     implementation did not properly handle socket unhashing     during spurious disconnects, which could lead to a     use-after-free flaw. On x86-64 architecture systems, a     local user able to create ping sockets could use this     flaw to crash the system. On non-x86-64 architecture     systems, a local user able to create ping sockets could     use this flaw to escalate their privileges on the     system.(CVE-2015-3636)

  - An inode data validation error was found in Linux     kernels built with UDF file system (CONFIG_UDF_FS)     support. An attacker able to mount a     corrupted/malicious UDF file system image could cause     the kernel to crash.(CVE-2015-4167)

  - 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 denial     of service on the system by holding a reference to the     ldisc lock during tty shutdown, causing a     deadlock.(CVE-2015-4170)

  - A flaw was discovered in the kernel's collect_mounts     function. If the kernel's audit subsystem called     collect_mounts to audit an unmounted path, it could     panic the system. With this flaw, an unprivileged user     could call umount(MNT_DETACH) to launch a     denial-of-service attack.(CVE-2015-4177)

  - A DoS flaw was found for a Linux kernel built for the     x86 architecture which had the KVM virtualization     support(CONFIG_KVM) enabled. The kernel would be     vulnerable to a NULL pointer dereference flaw in Linux     kernel's kvm_apic_has_events() function while doing an     ioctl. An unprivileged user able to access the     '/dev/kvm' device could use this flaw to crash the     system kernel.(CVE-2015-4692)

  - A flaw was found in the kernel's implementation of the     Berkeley Packet Filter (BPF). A local attacker could     craft BPF code to crash the system by creating a     situation in which the JIT compiler would fail to     correctly optimize the JIT image on the last pass. This     would lead to the CPU executing instructions that were     not part of the JIT code.(CVE-2015-4700)

  - A buffer overflow flaw was found in the way the Linux     kernel's virtio-net subsystem handled certain fraglists     when the GRO (Generic Receive Offload) functionality     was enabled in a bridged network configuration. An     attacker on the local network could potentially use     this flaw to crash the system, or, although unlikely,     elevate their privileges on the system.(CVE-2015-5156)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
199280	RHEL 7 : kernel (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	critical
124988	EulerOS Virtualization for ARM 64 3.0.1.0 : kernel (EulerOS-SA-2019-1535)	Nessus	Huawei Local Security Checks	high
124811	EulerOS Virtualization 3.0.1.0 : kernel (EulerOS-SA-2019-1487)	Nessus	Huawei Local Security Checks	high

Detections

Analytics

CVE-2015-4177

medium

Tenable Plugins

critical

high

high