Add advisory: asn1 BerReader infinite loop CPU DoS (CWE-835)

advisories/unreviewed/2026/05/asn1-berreader-dos/asn1-berreader-dos.json

@@ -0,0 +1,57 @@
+{
+  "schema_version": "1.4.0",
+  "id": "GHSA-PENDING",
+  "modified": "2026-05-01T00:00:00Z",
+  "published": "2026-05-01T00:00:00Z",
+  "aliases": [],
+  "summary": "asn1 BerReader.readString() infinite loop on malformed length (CPU DoS)",
+  "details": "BerReader.readString() in lib/ber/reader.js returns null when the decoded length exceeds the remaining buffer but does NOT advance _offset. Any code iterating children with `while (reader.remain > 0) { reader.readString(...) }` will spin forever: remain never decreases, peek() returns the same tag every iteration. Confirmed: a 2ms heartbeat timer fires 0 times during 200ms of synchronous looping — the Node.js event loop is completely blocked. A single 10-byte packet is sufficient. No authentication required.\n\nDownstream packages sshpk (extKeyUsage loop at x509.js:283), ldapjs (parse-to-message.js:70, pre-auth whole-process DoS), and @ldapjs/asn1 (carries identical fork of the bug) are also affected.",
+  "severity": [
+    {
+      "type": "CVSS_V3",
+      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
+    }
+  ],
+  "affected": [
+    {
+      "package": {
+        "ecosystem": "npm",
+        "name": "asn1"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "0"
+            }
+          ]
+        }
+      ],
+      "database_specific": {
+        "last_known_affected_version_range": "<= 0.2.6"
+      }
+    }
+  ],
+  "references": [
+    {
+      "type": "WEB",
+      "url": "https://github.com/TritonDataCenter/node-asn1/issues/57"
+    },
+    {
+      "type": "PACKAGE",
+      "url": "https://github.com/TritonDataCenter/node-asn1"
+    },
+    {
+      "type": "WEB",
+      "url": "https://www.npmjs.com/package/asn1"
+    }
+  ],
+  "database_specific": {
+    "cwe_ids": [
+      "CWE-835"
+    ],
+    "severity": "HIGH",
+    "github_reviewed": false
+  }
+}