OSV-2021-891 Heap-buffer-overflow in __cil_cat_expr_range_to_bitmap_helper
Not scored
Published
Check this codebase for OSV-2021-891 and fix it if it is affected.
What it is: OSV-2021-891 is a memory corruption vulnerability in selinux, published on 24 Jun 2021.
Exploitation: There is no known exploitation of OSV-2021-891 in the wild and no public exploit code.
Affected packages and fixed versions:
- selinux (OSS-Fuzz): affected all versions; no fix listed
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/OSV-2021-891/ (Markdown: https://insights.sbomify.com/OSV-2021-891/index.md)
A heap buffer overflow in the SELinux policy compiler allows attackers to cause denial of service or potentially execute code via crafted policy expressions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2021-891?
OSV-2021-891 is a memory corruption vulnerability in selinux, published on 24 Jun 2021.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35492
Crash type: Heap-buffer-overflow READ 4
Crash state:
__cil_cat_expr_range_to_bitmap_helper
__cil_expr_to_bitmap
__evaluate_cat_expression
Which versions are affected by OSV-2021-891?
1 open source package ship an affected version, including selinux.
| Package | Affected | Fixed in |
|---|---|---|
selinux OSS-Fuzz | All versions | None |
How do I fix OSV-2021-891?
No fix has been published for OSV-2021-891 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is OSV-2021-891 being exploited?
There is no known exploitation of OSV-2021-891 in the wild and no public exploit code.