JS: Decompression Bombs

javascript/ql/src/experimental/Security/CWE-522-DecompressionBombs/DecompressionBombs.qhelp

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+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+<overview>
+<p>Extracting Compressed files with any compression algorithm like gzip can cause to denial of service attacks.</p>
+<p>Attackers can compress a huge file which created by repeated similiar byte and convert it to a small compressed file.</p>
+
+</overview>
+<recommendation>
+
+<p>When you want to decompress a user-provided compressed file you must be careful about the decompression ratio or read these files within a loop byte by byte to be able to manage the decompressed size in each cycle of the loop.</p>
+
+</recommendation>
+<example>
+
+<p>
+JsZip: check uncompressedSize Object Field before extraction.
+</p>
+<sample src="jszip_good.js"/>
+
+<p>
+nodejs Zlib: use <a href="https://nodejs.org/dist/latest-v18.x/docs/api/zlib.html#class-options">maxOutputLength option</a> which it'll limit the buffer read size
+</p>
+<sample src="zlib_good.js" />
+
+<p>
+node-tar: use <a href="https://github.com/isaacs/node-tar/blob/8c5af15e43a769fd24aa7f1c84d93e54824d19d2/lib/list.js#L90">maxReadSize option</a> which it'll limit the buffer read size
+</p>
+<sample src="node-tar_good.js" />
+
+</example>
+<references>
+
+<li>
+<a href="https://github.com/advisories/GHSA-8225-6cvr-8pqp">CVE-2017-16129</a>
+</li>
+<li>
+<a href="https://www.bamsoftware.com/hacks/zipbomb/">A great research to gain more impact by this kind of attacks</a>
+</li>
+
+</references>
+</qhelp>

javascript/ql/src/experimental/Security/CWE-522-DecompressionBombs/DecompressionBombs.ql

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+/**
+ * @name User-controlled file decompression
+ * @description User-controlled data that flows into decompression library APIs without checking the compression rate is dangerous
+ * @kind path-problem
+ * @problem.severity error
+ * @security-severity 7.8
+ * @precision high
+ * @id js/user-controlled-data-decompression
+ * @tags security
+ *       experimental
+ *       external/cwe/cwe-522
+ */
+
+import javascript
+import DataFlow::PathGraph
+import DecompressionBombs
+
+class BombConfiguration extends TaintTracking::Configuration {
+  BombConfiguration() { this = "DecompressionBombs" }
+
+  override predicate isSource(DataFlow::Node source) { source instanceof RemoteFlowSource }
+
+  override predicate isSink(DataFlow::Node sink) { sink instanceof DecompressionBomb::Sink }
+
+  override predicate isAdditionalTaintStep(DataFlow::Node pred, DataFlow::Node succ) {
+    exists(DecompressionBomb::AdditionalTaintStep addstep |
+      addstep.isAdditionalTaintStep(pred, succ)
+    )
+  }
+}
+
+from BombConfiguration cfg, DataFlow::PathNode source, DataFlow::PathNode sink
+where cfg.hasFlowPath(source, sink)
+select sink.getNode(), source, sink, "This Decompression depends on a $@.", source.getNode(),
+  "potentially untrusted source"