Vulnerability · Published Dec 22, 2021 · Assigned by mitre
CVE-2021-44733
High 7.0
In plain English
A high-severity security flaw in the bpftool package (AlmaLinux). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)7.0High
Exploit odds (30 days)0.7%top 44.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC
Official description
A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11. This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | bpftool | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-abi-stablelists | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-cross-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-doc | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | python3-perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| Debian:12 | linux | 5.15.15-1 | DEBIAN-CVE-2021-44733 |
| Debian:13 | linux | 5.15.15-1 | DEBIAN-CVE-2021-44733 |
| Debian:14 | linux | 5.15.15-1 | DEBIAN-CVE-2021-44733 |
| Rocky Linux:8 | kernel | 0:4.18.0-372.9.1.el8 | RLSA-2022:1988 |
| Rocky Linux:8 | kernel-rt | 0:4.18.0-372.9.1.rt7.166.el8 | RLSA-2022:1975 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2021-44733 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2021-44733 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-44733 |
Affected products (as reported)
References
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/drivers/tee/tee_shm.c
- https://lore.kernel.org/lkml/20211215092501.1861229-1-jens.wiklander%40linaro.org/
- https://github.com/pjlantz/optee-qemu/blob/main/README.md
- https://security.netapp.com/advisory/ntap-20220114-0003/
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2941-1] linux-4.19 security update mailing-list
- DSA-5096 vendor-advisory
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=dfd0743f1d9ea76931510ed150334d571fbab49d