| Name | CVE-2021-3527 |
| Description | 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-2753-1, DLA-3099-1, ELA-481-1 |
| Debian Bugs | 988157 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| qemu (PTS) | jessie, jessie (lts) | 1:2.1+dfsg-12+deb8u23 | fixed |
| stretch (security) | 1:2.8+dfsg-6+deb9u17 | fixed | |
| stretch (lts), stretch | 1:2.8+dfsg-6+deb9u19 | fixed | |
| buster (security), buster, buster (lts) | 1:3.1+dfsg-8+deb10u12 | fixed | |
| bullseye | 1:5.2+dfsg-11+deb11u3 | fixed | |
| bullseye (security) | 1:5.2+dfsg-11+deb11u2 | fixed | |
| bookworm | 1:7.2+dfsg-7+deb12u7 | fixed | |
| sid, trixie | 1:9.1.1+ds-5 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| qemu | source | jessie | 1:2.1+dfsg-12+deb8u21 | ELA-481-1 | ||
| qemu | source | stretch | 1:2.8+dfsg-6+deb9u15 | DLA-2753-1 | ||
| qemu | source | buster | 1:3.1+dfsg-8+deb10u9 | DLA-3099-1 | ||
| qemu | source | (unstable) | 1:5.2+dfsg-11 | 988157 |
Initial patchset: https://lists.nongnu.org/archive/html/qemu-devel/2021-05/msg00564.html
Revisited: 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://gitlab.com/qemu-project/qemu/-/commit/7ec54f9eb62b5d177e30eb8b1cad795a5f8d8986
https://gitlab.com/qemu-project/qemu/-/commit/05a40b172e4d691371534828078be47e7fff524c
[jessie] - qemu <postponed> (Fix along in future ELA)