CVE-2020-36450 — bunch
HIGHCVE-2020-36450 is a high-severity (CVSS 8.1) CWE-77 vulnerability in bunch. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
Data races in bunch
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-36450 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
bunchReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
An issue was discovered in the bunch crate through 2020-11-12 for Rust.
Affected versions of this crate unconditionally implements Send/Sync for Bunch<T>.
This allows users to insert T: !Sync to Bunch<T>. It is possible to create a data race to a T: !Sync by invoking the Bunch::get() API (which returns &T) from multiple threads. It is also possible to send T: !Send to other threads by inserting T inside Bunch<T> and sending Bunch<T> to another thread, allowing to create a data race by inserting types like T = Rc<_>.
Such data races can lead to memory corruption.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | bunch | all versions | No fix |
Affected Products
bunchbunch_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for bunch, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of bunch has shipped for CVE-2020-36450 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Frequently Asked Questions
Is CVE-2020-36450 in your dependencies?
Find it across crates.io, including transitive dependencies.