Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.

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

  - Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu     5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value     is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this     is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However,     the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which     will fput() vm_file, leading to a refcount underflow. (CVE-2019-15794)

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

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:4356 advisory.

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

    Security Fix(es):
    * kernel: out-of-bounds reads in pinctrl subsystem (CVE-2020-0427)
    * kernel: Improper input validation in some Intel(R) Ethernet E810 Adapter drivers (CVE-2020-24502)
    * kernel: Insufficient access control in some Intel(R) Ethernet E810 Adapter drivers (CVE-2020-24503)
    * kernel: Uncontrolled resource consumption in some Intel(R) Ethernet E810 Adapter drivers     (CVE-2020-24504)
    * kernel: Fragmentation cache not cleared on reconnection (CVE-2020-24586)
    * kernel: Reassembling fragments encrypted under different keys (CVE-2020-24587)
    * kernel: wifi frame payload being parsed incorrectly as an L2 frame (CVE-2020-24588)
    * kernel: Forwarding EAPOL from unauthenticated wifi client (CVE-2020-26139)
    * kernel: accepting plaintext data frames in protected networks (CVE-2020-26140)
    * kernel: not verifying TKIP MIC of fragmented frames (CVE-2020-26141)
    * kernel: accepting fragmented plaintext frames in protected networks (CVE-2020-26143)
    * kernel: accepting unencrypted A-MSDU frames that start with RFC1042 header (CVE-2020-26144)
    * kernel: accepting plaintext broadcast fragments as full frames (CVE-2020-26145)
    * kernel: powerpc: RTAS calls can be used to compromise kernel integrity (CVE-2020-27777)
    * kernel: locking inconsistency in tty_io.c and tty_jobctrl.c can lead to a read-after-free     (CVE-2020-29660)
    * kernel: buffer overflow in mwifiex_cmd_802_11_ad_hoc_start function via a long SSID value     (CVE-2020-36158)
    * kernel: slab out-of-bounds read in hci_extended_inquiry_result_evt()  (CVE-2020-36386)
    * kernel: Improper access control in BlueZ may allow information disclosure vulnerability. (CVE-2021-0129)
    * kernel: Use-after-free in ndb_queue_rq() in drivers/block/nbd.c (CVE-2021-3348)
    * kernel: Linux kernel eBPF RINGBUF map oversized allocation (CVE-2021-3489)
    * kernel: double free in bluetooth subsystem when the HCI device initialization fails (CVE-2021-3564)
    * kernel: use-after-free in function hci_sock_bound_ioctl() (CVE-2021-3573)
    * kernel: eBPF 32-bit source register truncation on div/mod (CVE-2021-3600)
    * kernel: DoS in rb_per_cpu_empty() (CVE-2021-3679)
    * kernel: Mounting overlayfs inside an unprivileged user namespace can reveal files (CVE-2021-3732)
    * kernel: heap overflow in __cgroup_bpf_run_filter_getsockopt() (CVE-2021-20194)
    * kernel: Race condition in sctp_destroy_sock list_del (CVE-2021-23133)
    * kernel: fuse: stall on CPU can occur because a retry loop continually finds the same bad inode     (CVE-2021-28950)
    * kernel: System crash in intel_pmu_drain_pebs_nhm in arch/x86/events/intel/ds.c (CVE-2021-28971)
    * kernel: protection can be bypassed to leak content of kernel memory (CVE-2021-29155)
    * kernel: improper input validation in tipc_nl_retrieve_key function in net/tipc/node.c (CVE-2021-29646)
    * kernel: lack a full memory barrier may lead to DoS (CVE-2021-29650)
    * kernel: local escalation of privileges in handling of eBPF programs (CVE-2021-31440)
    * kernel: protection of stack pointer against speculative pointer arithmetic can be bypassed to leak     content of kernel memory (CVE-2021-31829)
    * kernel: out-of-bounds reads and writes due to enforcing incorrect limits for pointer arithmetic     operations by BPF verifier (CVE-2021-33200)
    * kernel: reassembling encrypted fragments with non-consecutive packet numbers (CVE-2020-26146)
    * kernel: reassembling mixed encrypted/plaintext fragments (CVE-2020-26147)
    * kernel: the copy-on-write implementation can grant unintended write access because of a race condition     in a THP mapcount check (CVE-2020-29368)
    * kernel: flowtable list del corruption with kernel BUG at lib/list_debug.c:50 (CVE-2021-3635)
    * kernel: NULL pointer dereference in llsec_key_alloc() in net/mac802154/llsec.c (CVE-2021-3659)
    * kernel: setsockopt System Call Untrusted Pointer Dereference Information Disclosure (CVE-2021-20239)
    * kernel: out of bounds array access in drivers/md/dm-ioctl.c (CVE-2021-31916)

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.

The remote Ubuntu 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-4209-1 advisory.

    Jann Horn discovered that the OverlayFS and ShiftFS Drivers in the Linux kernel did not properly handle     reference counting during memory mapping operations when used in conjunction with AUFS. A local attacker     could use this to cause a denial of service (system crash) or possibly execute arbitrary code.
    (CVE-2019-15794)

    It was discovered that a buffer overflow existed in the 802.11 Wi-Fi configuration interface for the Linux     kernel when handling beacon settings. A local attacker could use this to cause a denial of service (system     crash) or possibly execute arbitrary code. (CVE-2019-16746)

    It was discovered that there was a memory leak in the Advanced Buffer Management functionality of the     Netronome NFP4000/NFP6000 NIC Driver in the Linux kernel during certain error scenarios. A local attacker     could use this to cause a denial of service (memory exhaustion). (CVE-2019-19076)

Tenable has extracted the preceding description block directly from the Ubuntu 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 remote Ubuntu 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-4208-1 advisory.

    Jann Horn discovered that the OverlayFS and ShiftFS Drivers in the Linux kernel did not properly handle     reference counting during memory mapping operations when used in conjunction with AUFS. A local attacker     could use this to cause a denial of service (system crash) or possibly execute arbitrary code.
    (CVE-2019-15794)

    Nicolas Waisman discovered that the WiFi driver stack in the Linux kernel did not properly validate SSID     lengths. A physically proximate attacker could use this to cause a denial of service (system crash).
    (CVE-2019-17133)

    It was discovered that the ARM Komeda display driver for the Linux kernel did not properly deallocate     memory in certain error conditions. A local attacker could use this to cause a denial of service (memory     exhaustion). (CVE-2019-18810)

    It was discovered that the VirtualBox guest driver implementation in the Linux kernel did not properly     deallocate memory in certain error conditions. A local attacker could use this to cause a denial of     service (memory exhaustion). (CVE-2019-19048)

    It was discovered that the ADIS16400 IIO IMU Driver for the Linux kernel did not properly deallocate     memory in certain error conditions. A local attacker could use this to cause a denial of service (memory     exhaustion). (CVE-2019-19060, CVE-2019-19061)

    It was discovered that the Intel OPA Gen1 Infiniband Driver for the Linux kernel did not properly     deallocate memory in certain error conditions. A local attacker could use this to cause a denial of     service (memory exhaustion). (CVE-2019-19065)

    It was discovered that the AMD Audio Coprocessor driver for the Linux kernel did not properly deallocate     memory in certain error conditions. A local attacker with the ability to load modules could use this to     cause a denial of service (memory exhaustion). (CVE-2019-19067)

    It was discovered in the Qualcomm FastRPC Driver for the Linux kernel did not properly deallocate memory     in certain error conditions. A local attacker could use this to cause a denial of service (memory     exhaustion). (CVE-2019-19069)

    It was discovered that the Cascoda CA8210 SPI 802.15.4 wireless controller driver for the Linux kernel did     not properly deallocate memory in certain error conditions. A local attacker could use this to cause a     denial of service (memory exhaustion). (CVE-2019-19075)

    It was discovered that the AMD Display Engine Driver in the Linux kernel did not properly deallocate     memory in certain error conditions. A local attack could use this to cause a denial of service (memory     exhaustion). (CVE-2019-19083)

    Nicolas Waisman discovered that the Chelsio T4/T5 RDMA Driver for the Linux kernel performed DMA from a     kernel stack. A local attacker could use this to cause a denial of service (system crash).
    (CVE-2019-17075)

Tenable has extracted the preceding description block directly from the Ubuntu 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
222382	Linux Distros Unpatched Vulnerability : CVE-2019-15794	Nessus	Misc.	medium
155219	RHEL 8 : kernel (RHSA-2021:4356)	Nessus	Red Hat Local Security Checks	high
131563	Ubuntu 18.04 LTS : Linux kernel vulnerabilities (USN-4209-1)	Nessus	Ubuntu Local Security Checks	critical
131562	Ubuntu 18.04 LTS : Linux kernel vulnerabilities (USN-4208-1)	Nessus	Ubuntu Local Security Checks	critical

Detections

Analytics

CVE-2019-15794

medium

Tenable Plugins

medium

high

critical

critical