CVE-2021-29486 is a high-severity (CVSS 7.5) vulnerability in cumulative-distribution-function. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2021-29486 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
cumulative-distribution-function Infinite Loop vulnerability
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
cumulative-distribution-functionnpmDescription
Impact
- Apps using this library on improper data may crash or go into an infinite-loop
- In the case of a nodejs server-app using this library to act on invalid non-numeric data, the nodejs server may crash. This may affect other users of this server and/or require the server to be rebooted for proper operation.
- In the case of a browser app using this library to act on invalid non-numeric data, that browser may crash or lock up.
A flaw enabling an infinite-loop was discovered in the code for evaluating the cumulative-distribution-function
of input data. Although the documentation explains that numeric data is required, some users may confuse an array
of strings like ["1","2","3","4","5"] for numeric data [1,2,3,4,5] when it is in fact string data. An infinite loop is possible when the
cumulative-distribution-function is evaluated for a given point when the input data is string data rather than type number.
This vulnerability enables an infinite-cpu-loop denial-of-service-attack on any app using npm:cumulative-distribution-function v1.0.3 or earlier if the attacker can supply malformed data to the library. The vulnerability could also manifest if a data source to be analyzed changes data type from Arrays of number (proper) to Arrays of string (invalid, but undetected by earlier version of the library).
Patches
Users should upgrade to at least v2.0.0, or the latest version.
Tests for several types of invalid data have been created, and version 2.0.0 has been tested to reject this invalid data by
throwing a TypeError() instead of processing it. Developers using this library may wish to adjust their app's code slightly to better tolerate or handle this TypeError. Apps performing proper numeric data validation before sending data to this library should be mostly unaffected by this patch.
Workarounds
The vulnerability can be mitigated in older versions by ensuring that only finite numeric data of type Array[number] or number is passed to cumulative-distribution-function and its f(x) function, respectively.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the Github repository at https://github.com/DrPaulBrewer/cumulative-distribution-function
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | cumulative-distribution-function | all versions | 2.0.0 |
Research 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 cumulative-distribution-function. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update cumulative-distribution-function to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29486 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2021-29486 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-29486. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-29486 in your dependencies?
O3 detects CVE-2021-29486 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.