CVE-2024-27303 is a high-severity (CVSS 7.3) CWE-426 vulnerability in app-builder-lib. A fix is available for app-builder-lib — see the affected versions and patch details below.
electron-builder's NSIS installer - execute arbitrary code on the target machine (Windows only)
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2024-27303.
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-2024-27303 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 378,156 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.
app-builder-libnpmDescription
electron-builder is a solution to package and build a ready for distribution Electron, Proton Native app for macOS, Windows and Linux. A vulnerability that only affects eletron-builder prior to 24.13.2 in Windows, the NSIS installer makes a system call to open cmd.exe via NSExec in the .nsh installer script. NSExec by default searches the current directory of where the installer is located before searching PATH. This means that if an attacker can place a malicious executable file named cmd.exe in the same folder as the installer, the installer will run the malicious file. Version 24.13.2 fixes this issue. No known workaround exists. The code executes at the installer-level before the app is present on the system, so there's no way to check if it exists in a current installer.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | app-builder-lib | all versions | 24.13.2npm install app-builder-lib@24.13.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for app-builder-lib, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update app-builder-lib to 24.13.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27303 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-2024-27303 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-27303. 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-2024-27303 in your dependencies?
O3 Security finds CVE-2024-27303 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.