UBUNTU-CVE-2021-3527

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    UBUNTU-CVE-2021-3527

    Published: 26 May 2021Last Modified: 9 Jun 2026
    Upstream:
    CVE-2021-3527

    Summary:

    Details: 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.

    References: https://ubuntu.com/security/CVE-2021-3527, https://lists.nongnu.org/archive/html/qemu-devel/2021-05/msg00564.html, https://lists.nongnu.org/archive/html/qemu-devel/2021-05/msg01372.html, https://lists.nongnu.org/archive/html/qemu-devel/2021-05/msg01373.html, https://ubuntu.com/security/notices/USN-5010-1, https://www.cve.org/CVERecord?id=CVE-2021-3527, https://ubuntu.com/security/notices/USN-8412-1

    Affected packages

    Package

    Name: qemu

    Purl: pkg:deb/ubuntu/qemu?arch=source&distro=esm-infra-legacy%2Ftrusty

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -2.0.0+dfsg-2ubuntu1.47+esm6

    Affected versions

    1.5.0+dfsg-3ubuntu5
    1.5.0+dfsg-3ubuntu6

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    UBUNTU-CVE-2021-3527 | CVE-DB