CVE-2019-15543 — slice-deque
CRITICALCVE-2019-15543 is a critical-severity (CVSS 9.8) Out-of-bounds Write vulnerability in slice-deque. A fix is available for slice-deque — see the affected versions and patch details below.
Out of bounds write in slice-deque
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2019-15543 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
slice-dequeReal-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
Affected versions of this crate entered a corrupted state if mem::size_of::<T>() % allocation_granularity() != 0 and a specific allocation pattern was used: sufficiently shifting the deque elements over the mirrored page boundary.
This allows an attacker that controls controls both element insertion and removal to corrupt the deque, such that reading elements from it would read bytes corresponding to other elements in the deque. (e.g. a read of T could read some bytes from one value and some bytes from an adjacent one, resulting in a T whose value representation is not meaningful). This is undefined behavior.
The flaw was corrected by using a pair of pointers to track the head and tail of the deque instead of a pair of indices. This pair of pointers are represented using a Rust slice.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | slice-deque | all versions | 0.2.0cargo update -p slice-deque --precise 0.2.0 |
Affected Products
slice-dequeslice-deque_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for slice-deque, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update slice-deque to 0.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-15543 is resolved across your whole dependency graph.
Workarounds
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-2019-15543 in your dependencies?
Find it across crates.io, including transitive dependencies.