CVE-2018-20976 Use after free in n/a
High 7.8
Published
Updated
Check this codebase for CVE-2018-20976 and fix it if it is affected.
What it is: CVE-2018-20976 is a high-severity use after free vulnerability in Linux kernel, published on 19 Aug 2019. 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-2018-20976 in the wild and no public exploit code.
Affected product: Linux kernel. 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-2018-20976/ (Markdown: https://insights.sbomify.com/CVE-2018-20976/index.md)
A use-after-free vulnerability in the Linux kernel XFS filesystem allows attackers to potentially execute arbitrary code or escalate privileges.
- 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-2018-20976?
CVE-2018-20976 is a high-severity use after free vulnerability in Linux kernel, published on 19 Aug 2019. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An issue was discovered in fs/xfs/xfs_super.c in the Linux kernel before 4.18. A use after free exists, related to xfs_fs_fill_super failure.
Weakness: CWE-416
Which versions are affected by CVE-2018-20976?
It affects 1 product.
Linux distribution packages (40)
kernel Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-abi-whitelists Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debug Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debug-debuginfo Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debug-devel Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debuginfo Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debuginfo-common-x86_64 Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-devel Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-doc Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-headers Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools-debuginfo Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools-libs Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools-libs-devel Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
perf Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
perf-debuginfo Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
python-perf Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
python-perf-debuginfo Red Hat:rhel_aus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-abi-whitelists Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-bootwrapper Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debug Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debug-debuginfo Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debug-devel Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debuginfo Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debuginfo-common-ppc64le Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-debuginfo-common-x86_64 Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-devel Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-doc Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-headers Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools-debuginfo Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools-libs Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-tools-libs-devel Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
perf Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
perf-debuginfo Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
python-perf Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
python-perf-debuginfo Red Hat:rhel_e4s:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel Red Hat:rhel_tus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
kernel-abi-whitelists Red Hat:rhel_tus:7.3::server | All versions | 0:3.10.0-514.72.1.el7 |
Products include Linux kernel.
How do I fix CVE-2018-20976?
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-2018-20976 being exploited?
There is no known exploitation of CVE-2018-20976 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2018-20976, GHSA-2px5-xhf9-x464, RHSA-2020:0178, UBUNTU-CVE-2018-20976.