Vulnerability
Malicious code in class-synth (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (1aa63407d7400b4819d0739dedad0a32d9ae29b18509693c2e8763cf30275271) class-synth is advertised as a small class/style/date utility library, but its main entry (dist/index.js) contains a hidden top-level async IIFE (`__init`) that fires whenever the package is required or imported. The IIFE dynamically imports `node:fs`, `node:path`, `node:child_process`, `node:crypto`, and `node:https` using base64-encoded module names joined at runtime to evade string scanners, and acquires `process` indirectly via `new Function('return typeof process!== "undefined"? process: null;')`. It then recursively walks `process.cwd()` looking for any `.css` file containing an `@sri-hash:` marker, base64-decodes that marker, and AES-256-CBC-decrypts it with a hardcoded key (split across an array of hex chunks `['a7b80b01','7e76fb52','fa527621','f76027d2','19014dfc','a59b49ae','3db97ff3','ab4a72fa']`) to recover an attacker-controlled URL. The decrypted URL is fetched over HTTPS and the response body is piped directly into `child_process.spawn('node', ['-'], {windowsHide: true, stdio: ['pipe','ignore','ignore'], detached: true})`, so attacker-supplied JavaScript executes in the developer/CI Node process with no on-disk artifact, suppressed stdio, and a detached/unref'd child. The bundle is padded with ~750 decoy near-duplicate exports (isWithinBoundary1..200, applyPreset1..150, createSequenceStep1..250, mapOperation1..250, checkConstraint1..250) to bury the dropper near the end of the file. The C2 URL is delivered out-of-band via a planted.css file, which defeats URL-based scanning of the package itself. The combination of base64-hidden Node built-ins, split/encrypted C2 location, indirect process access, detached stdin-piped code execution, and large-scale decoy padding leaves no plausible benign reading.
No CVSS base score from NVD or GHSA yet. NVD typically scores within 24–72 hours of publication; GHSA usually within a day for OSS-flagged CVEs. Last record update .
For interim severity, fall back on KEV / EXPLOIT signals and the EPSS percentile (lower panel). Re-check this CVE after one cron tick — the score lands automatically when the source publishes.
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No exploitation, limited impact or prevalence