CVE-2021-33909 Integer overflow in n/a
High 7.8
Published
Updated
Check this codebase for CVE-2021-33909 and fix it if it is affected.
What it is: CVE-2021-33909 is a high-severity vulnerability in Debian Debian Linux, published on 20 Jul 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-2021-33909 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-2021-33909/ (Markdown: https://insights.sbomify.com/CVE-2021-33909/index.md)
An integer overflow in the Linux kernel seq_file allows unprivileged users to escalate privileges to root via out-of-bounds write.
- 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-2021-33909?
CVE-2021-33909 is a high-severity vulnerability in Debian Debian Linux, published on 20 Jul 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.
Which versions are affected by CVE-2021-33909?
It affects 7 products.
Linux distribution packages (40)
bpftool Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
bpftool-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-abi-whitelists Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-core Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debug Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debug-core Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debug-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debug-devel Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debug-modules Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debug-modules-extra Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debuginfo-common-aarch64 Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debuginfo-common-ppc64le Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debuginfo-common-s390x Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-debuginfo-common-x86_64 Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-devel Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-doc Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-modules Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-modules-extra Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-tools Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-tools-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-tools-libs Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-zfcpdump Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-zfcpdump-core Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-zfcpdump-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-zfcpdump-devel Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-zfcpdump-modules Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kernel-zfcpdump-modules-extra Red Hat:rhel_eus:8.1::baseos | All versions | 0:4.18.0-147.51.2.el8_1 |
kpatch-patch-4_18_0-147_24_2 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-11.el8_1 |
kpatch-patch-4_18_0-147_24_2-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-11.el8_1 |
kpatch-patch-4_18_0-147_24_2-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-11.el8_1 |
kpatch-patch-4_18_0-147_27_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-11.el8_1 |
kpatch-patch-4_18_0-147_27_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-11.el8_1 |
kpatch-patch-4_18_0-147_27_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-11.el8_1 |
kpatch-patch-4_18_0-147_32_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-9.el8_1 |
kpatch-patch-4_18_0-147_32_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-9.el8_1 |
kpatch-patch-4_18_0-147_32_1-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-9.el8_1 |
kpatch-patch-4_18_0-147_34_1 Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-9.el8_1 |
kpatch-patch-4_18_0-147_34_1-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 0:1-9.el8_1 |
Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Netapp Hci Management Node, Netapp Solidfire, Oracle Communications Session Border Controller and 1 more.
How do I fix CVE-2021-33909?
Apply the vendor's patch.
Is CVE-2021-33909 being exploited?
There is no known exploitation of CVE-2021-33909 in the wild and no public exploit code.
Public exploit code: 4 proofs of concept on GitHub.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as A-195082750, ASB-A-195082750, AZL-6565, CLSA-2021-1632261963, CLSA-2021-1632261987, DEBIAN-CVE-2021-33909 and 6 more.