CVE-2021-33034 Use after free in n/a
High 7.8
Published
Updated
Check this codebase for CVE-2021-33034 and fix it if it is affected.
What it is: CVE-2021-33034 is a high-severity use after free vulnerability in Debian Debian Linux, published on 14 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-33034 in the wild and no public exploit code.
Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2021-33034/ (Markdown: https://insights.sbomify.com/CVE-2021-33034/index.md)
A use-after-free in the Linux kernel Bluetooth subsystem allows attackers to write arbitrary values, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-33034?
CVE-2021-33034 is a high-severity use after free vulnerability in Debian Debian Linux, published on 14 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. This leads to writing an arbitrary value.
Weakness: CWE-416
Which versions are affected by CVE-2021-33034?
It affects 3 products.
Linux distribution packages (30)
kpatch-patch-4_18_0-305 Red Hat:enterprise_linux:8::baseos | All versions | 0:1-2.el8 |
kpatch-patch-4_18_0-305-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:1-2.el8 |
kpatch-patch-4_18_0-305-debugsource Red Hat:enterprise_linux:8::baseos | All versions | 0:1-2.el8 |
kpatch-patch-4_18_0-305_3_1 Red Hat:enterprise_linux:8::baseos | All versions | 0:1-1.el8_4 |
kpatch-patch-4_18_0-305_3_1-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:1-1.el8_4 |
kpatch-patch-4_18_0-305_3_1-debugsource Red Hat:enterprise_linux:8::baseos | All versions | 0:1-1.el8_4 |
kpatch-patch-4_18_0-147_24_2 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-10.el8_1 |
kpatch-patch-4_18_0-147_24_2-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-10.el8_1 |
kpatch-patch-4_18_0-147_24_2-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-10.el8_1 |
kpatch-patch-4_18_0-147_27_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-10.el8_1 |
kpatch-patch-4_18_0-147_27_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-10.el8_1 |
kpatch-patch-4_18_0-147_27_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-10.el8_1 |
kpatch-patch-4_18_0-147_32_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-8.el8_1 |
kpatch-patch-4_18_0-147_32_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-8.el8_1 |
kpatch-patch-4_18_0-147_32_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-8.el8_1 |
kpatch-patch-4_18_0-147_34_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-8.el8_1 |
kpatch-patch-4_18_0-147_34_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-8.el8_1 |
kpatch-patch-4_18_0-147_34_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-8.el8_1 |
kpatch-patch-4_18_0-147_38_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-7.el8_1 |
kpatch-patch-4_18_0-147_38_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-7.el8_1 |
kpatch-patch-4_18_0-147_38_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-7.el8_1 |
kpatch-patch-4_18_0-147_43_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-5.el8_1 |
kpatch-patch-4_18_0-147_43_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-5.el8_1 |
kpatch-patch-4_18_0-147_43_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-5.el8_1 |
kpatch-patch-4_18_0-147_44_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-4.el8_1 |
kpatch-patch-4_18_0-147_44_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-4.el8_1 |
kpatch-patch-4_18_0-147_44_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-4.el8_1 |
kpatch-patch-4_18_0-147_48_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-1.el8_1 |
kpatch-patch-4_18_0-147_48_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-1.el8_1 |
kpatch-patch-4_18_0-147_48_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-1.el8_1 |
Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel.
How do I fix CVE-2021-33034?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2021-33034 being exploited?
There is no known exploitation of CVE-2021-33034 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as A-194694600, AZL-6562, DEBIAN-CVE-2021-33034, GHSA-3qpw-8jg3-xjrh, PUB-A-194694600, RHSA-2021:2563 and 2 more.