A potential DoS flaw was found in the virtio-fs shared file system daemon (virtiofsd) implementation of the QEMU version >= v5.0. Virtio-fs is meant to share a host file system directory with a guest via virtio-fs device. If the guest opens the maximum number of file descriptors under the shared directory, a denial of service may occur. This flaw allows a guest user/process to cause this denial of service on the host.

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

  - A potential DoS flaw was found in the virtio-fs shared file system daemon (virtiofsd) implementation of     the QEMU version >= v5.0. Virtio-fs is meant to share a host file system directory with a guest via     virtio-fs device. If the guest opens the maximum number of file descriptors under the shared directory, a     denial of service may occur. This flaw allows a guest user/process to cause this denial of service on the     host. (CVE-2020-10717)

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

The remote CentOS Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the qemu-kvm-6.1.0-3.el9 build changelog.

  - use-after-free during packet reassembly [rhel-av-8]) (CVE-2019-15890)

  - A flaw was found in QEMU in the implementation of the Pointer Authentication (PAuth) support for ARM     introduced in version 4.0 and fixed in version 5.0.0. A general failure of the signature generation     process caused every PAuth-enforced pointer to be signed with the same signature. A local attacker could     obtain the signature of a protected pointer and abuse this flaw to bypass PAuth protection for all     programs running on QEMU. (CVE-2020-10702)

  - A potential DoS flaw was found in the virtio-fs shared file system daemon (virtiofsd) implementation of     the QEMU version >= v5.0. Virtio-fs is meant to share a host file system directory with a guest via     virtio-fs device. If the guest opens the maximum number of file descriptors under the shared directory, a     denial of service may occur. This flaw allows a guest user/process to cause this denial of service on the     host. (CVE-2020-10717)

  - An out-of-bounds read vulnerability was found in the SLiRP networking implementation of the QEMU emulator.
    This flaw occurs in the icmp6_send_echoreply() routine while replying to an ICMP echo request, also known     as ping. This flaw allows a malicious guest to leak the contents of the host memory, resulting in possible     information disclosure. This flaw affects versions of libslirp before 4.3.1. (CVE-2020-10756)

  - An assertion failure issue was found in the Network Block Device(NBD) Server in all QEMU versions before     QEMU 5.0.1. This flaw occurs when an nbd-client sends a spec-compliant request that is near the boundary     of maximum permitted request length. A remote nbd-client could use this flaw to crash the qemu-nbd server     resulting in a denial of service. (CVE-2020-10761)

  - out-of-bounds r/w access issue while processing usb packets [rhel-av-8.3.0]) (CVE-2020-14364)

  - OOB heap access via an unexpected response of iSCSI Server [rhel-av-8.2.0]) (CVE-2020-1711)

  - A use after free vulnerability in ip_reass() in ip_input.c of libslirp 4.2.0 and prior releases allows     crafted packets to cause a denial of service. (CVE-2020-1983)

  - A flaw was found in the memory management API of QEMU during the initialization of a memory region cache.
    This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO     operations. A guest user may abuse this flaw to crash the QEMU process on the host, resulting in a denial     of service. This flaw affects QEMU versions prior to 5.2.0. (CVE-2020-27821)

  - A flaw was found in qemu. A host privilege escalation issue was found in the virtio-fs shared file system     daemon where a privileged guest user is able to create a device special file in the shared directory and     use it to r/w access host devices. (CVE-2020-35517)

  - OOB buffer access while emulating tcp protocols in tcp_emu() [rhel-av-8.2.0]) (CVE-2020-7039)

  - potential OOB access due to unsafe snprintf() usages [rhel-av-8.2.0]) (CVE-2020-8608)

  - An out-of-bounds heap buffer access issue was found in the ARM Generic Interrupt Controller emulator of     QEMU up to and including qemu 4.2.0on aarch64 platform. The issue occurs because while writing an     interrupt ID to the controller memory area, it is not masked to be 4 bits wide. It may lead to the said     issue while updating controller state fields and their subsequent processing. A privileged guest user may     use this flaw to crash the QEMU process on the host resulting in DoS scenario. (CVE-2021-20221)

  - A flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU. The new 'xattrmap' option     may cause the 'security.capability' xattr in the guest to not drop on file write, potentially leading to a     modified, privileged executable in the guest. In rare circumstances, this flaw could be used by a     malicious user to elevate their privileges within the guest. (CVE-2021-20263)

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

The remote host is affected by the vulnerability described in GLSA-202011-09 (QEMU: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in QEMU. Please review the       CVE identifiers referenced below for details.
  Impact :

    Please review the referenced CVE identifiers for details.
  Workaround :

    There is no known workaround at this time.

ID	Name	Product	Family	Severity
222982	Linux Distros Unpatched Vulnerability : CVE-2020-10717	Nessus	Misc.	medium
191255	CentOS 9 : qemu-kvm-6.1.0-3.el9	Nessus	CentOS Local Security Checks	high
142843	GLSA-202011-09 : QEMU: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	medium

Detections

Analytics

CVE-2020-10717

medium

Tenable Plugins

medium

high

medium