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Debian LTS Advisory DLA-2623-1                [email protected]
https://www.debian.org/lts/security/                      Markus Koschany
April 10, 2021                                https://wiki.debian.org/LTS
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Package        : qemu
Version        : 1:2.8+dfsg-6+deb9u14
CVE ID         : CVE-2020-17380 CVE-2021-3392 CVE-2021-3409 CVE-2021-3416 
                 CVE-2021-20203 CVE-2021-20255 CVE-2021-20257
Debian Bug     : 984450 984451 984452 984448 984449 970937

Several security vulnerabilities have been discovered in QEMU, a fast processor
emulator.

CVE-2021-20257

    net: e1000: infinite loop while processing transmit descriptors


CVE-2021-20255

    A stack overflow via an infinite recursion vulnerability was found in the
    eepro100 i8255x device emulator of QEMU. This issue occurs while processing
    controller commands due to a DMA reentry issue. This flaw allows a guest
    user or process to consume CPU cycles or crash the QEMU process on the
    host, resulting in a denial of service.

CVE-2021-20203

    An integer overflow issue was found in the vmxnet3 NIC emulator of the
    QEMU. It may occur if a guest was to supply invalid values for rx/tx queue
    size or other NIC parameters. A privileged guest user may use this flaw to
    crash the QEMU process on the host resulting in DoS scenario.

CVE-2021-3416

    A potential stack overflow via infinite loop issue was found in various NIC
    emulators of QEMU in versions up to and including 5.2.0. The issue occurs
    in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A
    guest user/process may use this flaw to consume CPU cycles or crash the
    QEMU process on the host resulting in DoS scenario.


CVE-2021-3416

    The patch for CVE-2020-17380/CVE-2020-25085 was found to be ineffective,
    thus making QEMU vulnerable to the out-of-bounds read/write access issues
    previously found in the SDHCI controller emulation code. This flaw allows a
    malicious privileged guest to crash the QEMU process on the host, resulting
    in a denial of service or potential code execution.

For Debian 9 stretch, these problems have been fixed in version
1:2.8+dfsg-6+deb9u14.

We recommend that you upgrade your qemu packages.

For the detailed security status of qemu please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/qemu

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS