Resource exhaustion in Qemu
CVE-2021-3527
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.
EPSS: 0.004 (29.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Qemu
- Debian Debian_linux — versions 9.0, 10.0
- Redhat Enterprise_linux — versions 8.0
- N/a Qemu — versions all versions
Weakness classification (CWE)
References
- secalert@redhat.com (Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)
- secalert@redhat.com (Patch, Mailing List, Third Party Advisory, x_refsource_MISC)
- secalert@redhat.com (Patch, Third Party Advisory, x_refsource_MISC)
- secalert@redhat.com (Patch, Third Party Advisory, x_refsource_MISC)
- secalert@redhat.com (x_refsource_CONFIRM, Third Party Advisory)
- secalert@redhat.com (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- secalert@redhat.com (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- secalert@redhat.com (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-3527?
- CVE-2021-3527 is a medium-severity vulnerability in Qemu, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.5/10. Published 2021-05-26.
- How severe is CVE-2021-3527?
- Medium severity. CVSS v3 base score is 5.5 out of 10.