| Name | CVE-2016-4020 |
| Description | The patch_instruction function in hw/i386/kvmvapic.c in QEMU does not initialize the imm32 variable, which allows local guest OS administrators to obtain sensitive information from host stack memory by accessing the Task Priority Register (TPR). |
| 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-1599-1, DLA-573-1, DLA-574-1 |
| Debian Bugs | 821062 |
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 | wheezy | 1.1.2+dfsg-6+deb7u14 | DLA-573-1 | ||
| qemu | source | jessie | 1:2.1+dfsg-12+deb8u8 | DLA-1599-1 | ||
| qemu | source | (unstable) | 1:2.6+dfsg-2 | 821062 | ||
| qemu-kvm | source | wheezy | 1.1.2+dfsg-6+deb7u14 | DLA-574-1 | ||
| qemu-kvm | source | (unstable) | (unfixed) |
https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg01118.html
https://bugzilla.redhat.com/show_bug.cgi?id=1313686
https://www.openwall.com/lists/oss-security/2016/04/13/6