CVE-2022-37603 is a high-severity (CVSS 7.5) CWE-1333 vulnerability in loader-utils. 2 public exploit references exist, so weaponization risk is real. A fix is available for loader-utils — see the affected versions and patch details below.
loader-utils is vulnerable to Regular Expression Denial of Service (ReDoS) via url variable
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-2022-37603.
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-2022-37603 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 377,636 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.
loader-utilsnpmDescription
A Regular expression denial of service (ReDoS) flaw was found in Function interpolateName in interpolateName.js in webpack loader-utils 2.0.0 via the url variable in interpolateName.js. A badly or maliciously formed string could be used to send crafted requests that cause a system to crash or take a disproportional amount of time to process. This issue has been patched in versions 1.4.2, 2.0.4 and 3.2.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | loader-utils | ≥ 1.0.0&&< 1.4.2 | 1.4.2npm install loader-utils@1.4.2 |
| 📦npm | loader-utils | ≥ 2.0.0&&< 2.0.4 | 2.0.4npm install loader-utils@2.0.4 |
| 📦npm | loader-utils | ≥ 3.0.0&&< 3.2.1 | 3.2.1npm install loader-utils@3.2.1 |
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 loader-utils, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update loader-utils to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-37603 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-2022-37603 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-37603. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Migration Toolkit for Runtimes 1 on RHEL 8 | see advisory | RHSA-2023:0471 |
| Migration Toolkit for Runtimes 1 on RHEL 8 | loader-utils | RHSA-2023:3374 |
| MTA-6.0-RHEL-8 | mta/mta-ui-rhel8:6.0.1-10 | RHSA-2023:0934 |
| Red Hat Data Grid 8.4.1 | loader-utils | RHSA-2023:0713 |
| Red Hat Migration Toolkit for Containers 1.7 | rhmtc/openshift-migration-ui-rhel8:v1.7.8-5 | RHSA-2023:1428 |
| Red Hat Single Sign-On 7 | loader-utils | RHSA-2023:1049 |
| Red Hat Single Sign-On 7.6 for RHEL 7 | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el7sso | RHSA-2023:1043 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el8sso | RHSA-2023:1044 |
Frequently Asked Questions
Is CVE-2022-37603 in your dependencies?
O3 Security finds CVE-2022-37603 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.