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 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
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

critical

critical