OESA-2021-1241

QEMU is a FAST! processor emulator using dynamic translation to achieve good emulation speed.

Security Fix(es):

A NULL pointer dereference flaw was found in the SCSI emulation support of QEMU in versions before 6.0.0. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.(CVE-2020-35504)

A flaw was found in the USB redirector device (usb-redir) of QEMU. Small USB packets are combined into a single, large transfer request, to reduce the overhead and improve performance. The combined size of the bulk transfer is used to dynamically allocate a variable length array (VLA) on the stack without proper validation. Since the total size is not bounded, a malicious guest could use this flaw to influence the array length and cause the QEMU process to perform an excessive allocation on the stack, resulting in a denial of service.(CVE-2021-3527)

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 NULL pointer dereference flaw was found in the am53c974 SCSI host bus adapter emulation of QEMU in versions before 6.0.0. This issue occurs while handling the 'Information Transfer' command. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.(CVE-2020-35505)

The ahcicommitbuf function in ide/ahci.c in QEMU allows attackers to cause a denial of service (NULL dereference) when the command header 'ad->cur_cmd' is null.(CVE-2019-12067)