OSV-2021-838 Heap-use-after-free in multiline_parser_conf_file
Not scored
Published
Check this codebase for OSV-2021-838 and fix it if it is affected.
What it is: OSV-2021-838 is an use after free vulnerability in fluent-bit, published on 7 Jun 2021.
Exploitation: There is no known exploitation of OSV-2021-838 in the wild and no public exploit code.
Affected packages and fixed versions:
- fluent-bit (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-2021-838/ (Markdown: https://insights.sbomify.com/OSV-2021-838/index.md)
A heap-use-after-free vulnerability in Fluent Bit's multiline parser allows attackers to potentially execute code or cause a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2021-838?
OSV-2021-838 is an use after free vulnerability in fluent-bit, published on 7 Jun 2021.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34960
Crash type: Heap-use-after-free READ 8
Crash state:
multiline_parser_conf_file
flb_parser_conf_file
config_fuzzer.c
Which versions are affected by OSV-2021-838?
1 open source package ship an affected version, including fluent-bit.
| Package | Affected | Fixed in |
|---|---|---|
fluent-bit OSS-Fuzz | All versions | None |
How do I fix OSV-2021-838?
No fix has been published for OSV-2021-838 yet. Limit exposure of the affected software until one is available.
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 OSV-2021-838 being exploited?
There is no known exploitation of OSV-2021-838 in the wild and no public exploit code.