{"url":"http://public2.vulnerablecode.io/api/packages/759162?format=json","purl":"pkg:npm/%40lodestar/reqresp@1.4.0-dev.230ece4d72","type":"npm","namespace":"@lodestar","name":"reqresp","version":"1.4.0-dev.230ece4d72","qualifiers":{},"subpath":"","is_vulnerable":true,"next_non_vulnerable_version":"1.25.0","latest_non_vulnerable_version":"1.25.0","affected_by_vulnerabilities":[{"url":"http://public2.vulnerablecode.io/api/vulnerabilities/29386?format=json","vulnerability_id":"VCID-3afj-3119-7kfa","summary":"Lodestar snappy checksum issue\n### Impact\nUnintended permanent chain split affecting greater than or equal to 25% of the network, requiring hard fork (network partition requiring hard fork)\n\nLodestar does not verify checksum in snappy framing uncompressed chunks.\n\n### Vulnerability Details\nIn Req/Resp protocol the messages are encoded by using ssz_snappy encoding, which is a snappy framing compression over ssz encoded message.\n\nIn snappy framing format there are uncompressed chunks, each such chunk is prefixed with a checksum.\n\nLet's see how golang implementation parses such chunks - https://github.com/golang/snappy/blob/master/decode.go#L176\n\n```\n\tcase chunkTypeUncompressedData:\n\t\t\t// Section 4.3. Uncompressed data (chunk type 0x01).\n\t\t\tif chunkLen < checksumSize {\n\t\t\t\tr.err = ErrCorrupt\n\t\t\t\treturn r.err\n\t\t\t}\n\t\t\tbuf := r.buf[:checksumSize]\n\t\t\tif !r.readFull(buf, false) {\n\t\t\t\treturn r.err\n\t\t\t}\n\t\t\tchecksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24\n\t\t\t// Read directly into r.decoded instead of via r.buf.\n\t\t\tn := chunkLen - checksumSize\n\t\t\tif n > len(r.decoded) {\n\t\t\t\tr.err = ErrCorrupt\n\t\t\t\treturn r.err\n\t\t\t}\n\t\t\tif !r.readFull(r.decoded[:n], false) {\n\t\t\t\treturn r.err\n\t\t\t}\n\t\t\tif crc(r.decoded[:n]) != checksum {\n\t\t\t\tr.err = ErrCorrupt\n\t\t\t\treturn r.err\n\t\t\t}\n\t\t\tr.i, r.j = 0, n\n\t\t\tcontinue\n```\n\nAs you can see, if checksum is incorrect, decoder fails and returns error.\n\nNow let's look at lodestar decoder https://github.com/ChainSafe/lodestar/blob/unstable/packages/reqresp/src/encodingStrategies/sszSnappy/snappyFrames/uncompress.ts#L17\n\n```\nuncompress(chunk: Uint8ArrayList): Uint8ArrayList | null {\n    this.buffer.append(chunk);\n    const result = new Uint8ArrayList();\n    while (this.buffer.length > 0) {\n      if (this.buffer.length < 4) break;\n\n      const type = getChunkType(this.buffer.get(0));\n      const frameSize = getFrameSize(this.buffer, 1);\n\n      if (this.buffer.length - 4 < frameSize) {\n        break;\n      }\n\n      const data = this.buffer.subarray(4, 4 + frameSize);\n      this.buffer.consume(4 + frameSize);\n\n      if (!this.state.foundIdentifier && type !== ChunkType.IDENTIFIER) {\n        throw \"malformed input: must begin with an identifier\";\n      }\n\n      if (type === ChunkType.IDENTIFIER) {\n        if (!Buffer.prototype.equals.call(data, IDENTIFIER)) {\n          throw \"malformed input: bad identifier\";\n        }\n        this.state.foundIdentifier = true;\n        continue;\n      }\n\n      if (type === ChunkType.COMPRESSED) {\n        result.append(uncompress(data.subarray(4)));\n      }\n      if (type === ChunkType.UNCOMPRESSED) {\n1)        result.append(data.subarray(4));\n      }\n    }\n    if (result.length === 0) {\n      return null;\n    }\n    return result;\n  }\n```\n\nAs you can see, checksum is not verified, bytes are appended to 'result'\n\n### Proof of Concept\n\nHow to reproduce:\n\nget poc via [gist link](https://gist.github.com/gln7/aab55674431b1c8d42a59ccf9d7cbf60) and run it:\n\n```\n$ node dec1.mjs \nchecking chunk type=255\nchecking chunk type=1\ngot uncompressed chunk..\nDecompressed ok 124 bytes\n```","references":[{"reference_url":"https://github.com/ChainSafe/lodestar","reference_id":"","reference_type":"","scores":[{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/ChainSafe/lodestar"},{"reference_url":"https://github.com/ChainSafe/lodestar/commit/18a0d681dbcc51fb2ac9456f31e91f4e31a18300","reference_id":"","reference_type":"","scores":[{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/ChainSafe/lodestar/commit/18a0d681dbcc51fb2ac9456f31e91f4e31a18300"},{"reference_url":"https://github.com/ChainSafe/lodestar/security/advisories/GHSA-m9c9-mc2h-9wjw","reference_id":"","reference_type":"","scores":[{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/ChainSafe/lodestar/security/advisories/GHSA-m9c9-mc2h-9wjw"},{"reference_url":"https://github.com/advisories/GHSA-m9c9-mc2h-9wjw","reference_id":"GHSA-m9c9-mc2h-9wjw","reference_type":"","scores":[],"url":"https://github.com/advisories/GHSA-m9c9-mc2h-9wjw"}],"fixed_packages":[{"url":"http://public2.vulnerablecode.io/api/packages/62888?format=json","purl":"pkg:npm/%40lodestar/reqresp@1.25.0","is_vulnerable":false,"affected_by_vulnerabilities":[],"resource_url":"http://public2.vulnerablecode.io/packages/pkg:npm/%2540lodestar/reqresp@1.25.0"}],"aliases":["GHSA-m9c9-mc2h-9wjw"],"risk_score":null,"exploitability":null,"weighted_severity":null,"resource_url":"http://public2.vulnerablecode.io/vulnerabilities/VCID-3afj-3119-7kfa"},{"url":"http://public2.vulnerablecode.io/api/vulnerabilities/29640?format=json","vulnerability_id":"VCID-9k1r-va4y-rbea","summary":"Lodestar snappy decompression issue\n### Impact\nUnintended permanent chain split affecting greater than or equal to 25% of the network, requiring hard fork (network partition requiring hard fork)\n\n### Description\nLodestar client may fail to decode snappy framing compressed messages.\n\n### Vulnerability Details\nIn Req/Resp protocol the message are encoded by using ssz_snappy encoding, which is basically snappy framing compression over ssz encoded message.\n\nIt's mentioned here - https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md\n\n```\nThe token of the negotiated protocol ID specifies the type of encoding to be used for the req/resp interaction. Only one value is possible at this time:\n\nssz_snappy: The contents are first SSZ-encoded and then compressed with Snappy frames compression. For objects containing a single field, only the field is SSZ-encoded not a container with a single field. For example, the BeaconBlocksByRoot request is an SSZ-encoded list of Root's. This encoding type MUST be supported by all clients.\n```\n\nIn snappy framing format there a few types of chunks.\nWe are interested in so called reserved skippable chunks. These are chunks with chunk type in range [0x80, 0xfd]\nLet's see how rust snappy handles them https://github.com/BurntSushi/rust-snappy/blob/master/src/read.rs#L137\n\n```\nimpl<R: io::Read> io::Read for FrameDecoder<R> {\n    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {\n \t\t   ... \n           ...\n  \t\t    let len = len64 as usize;\n            match ty {\n                Err(b) if 0x02 <= b && b <= 0x7F => {\n                    // Spec says that chunk types 0x02-0x7F are reserved and\n                    // conformant decoders must return an error.\n                    fail!(Error::UnsupportedChunkType { byte: b });\n                }\n                Err(b) if 0x80 <= b && b <= 0xFD => {\n                    // Spec says that chunk types 0x80-0xFD are reserved but\n                    // skippable.\n                    self.r.read_exact(&mut self.src[0..len])?;\n                }\n```\n\nSimilar code can be found in golang implementation - https://github.com/golang/snappy/blob/master/decode.go#L221\n\n```\nfunc (r *Reader) fill() error {\n\t...\n\tif chunkType <= 0x7f {\n\t\t\t// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).\n\t\t\tr.err = ErrUnsupported\n\t\t\treturn r.err\n\t\t}\n\t\t// Section 4.4 Padding (chunk type 0xfe).\n\t\t// Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd).\n\t\tif !r.readFull(r.buf[:chunkLen], false) {\n\t\t\treturn r.err\n\t\t}\n```\n\nNow let's see how lodestar handles such chunks https://github.com/ChainSafe/lodestar/blob/unstable/packages/reqresp/src/encodingStrategies/sszSnappy/snappyFrames/uncompress.ts#L17\n\n```\nuncompress(chunk: Uint8ArrayList): Uint8ArrayList | null {\n    this.buffer.append(chunk);\n    const result = new Uint8ArrayList();\n    while (this.buffer.length > 0) {\n      if (this.buffer.length < 4) break;\n\n      const type = getChunkType(this.buffer.get(0));\n      const frameSize = getFrameSize(this.buffer, 1);\n\n      if (this.buffer.length - 4 < frameSize) {\n        break;\n      }\n\n      const data = this.buffer.subarray(4, 4 + frameSize);\n      this.buffer.consume(4 + frameSize);\n\n      if (!this.state.foundIdentifier && type !== ChunkType.IDENTIFIER) {\n        throw \"malformed input: must begin with an identifier\";\n      }\n\n      if (type === ChunkType.IDENTIFIER) {\n        if (!Buffer.prototype.equals.call(data, IDENTIFIER)) {\n          throw \"malformed input: bad identifier\";\n        }\n        this.state.foundIdentifier = true;\n        continue;\n      }\n\n      if (type === ChunkType.COMPRESSED) {\n        result.append(uncompress(data.subarray(4)));\n      }\n      if (type === ChunkType.UNCOMPRESSED) {\n        result.append(data.subarray(4));\n      }\n    }\n    if (result.length === 0) {\n      return null;\n    }\n    return result;\n  }\n\n function getChunkType(value: number): ChunkType {\n  switch (value) {\n    case ChunkType.IDENTIFIER:\n      return ChunkType.IDENTIFIER;\n    case ChunkType.COMPRESSED:\n      return ChunkType.COMPRESSED;\n    case ChunkType.UNCOMPRESSED:\n      return ChunkType.UNCOMPRESSED;\n    case ChunkType.PADDING:\n      return ChunkType.PADDING;\n    default:\n      throw new Error(\"Unsupported snappy chunk type\");\n  }\n```\n\nAs you can see, lodestar does not recognize such chunks.\n\nIf it sees such chunk, function getChunkType() throws an exception and decoding fails.\n\n### Impact Details\n\nFaulty nodes may trigger chain stall by sending messages which lodestar fails to parse, while other clients will be able to handle.\n\n### Proof of Concept\n\nHow to reproduce:\n\n1. get archive (via provided [gist link](https://gist.github.com/gln7/bdde7f4e0bdf9d47bf810a015796867a)), decode and unpack it:\n```\n$ base64 -d poc.txt > poc.tgz\n$ tar zxf poc.tgz\n```\n\n2. run dec1.go to verify that our snappy file decompressed successfully\n```\n$ go run dec1.go\n\nreading 1.snappy...\nread 124 bytes, err <nil>\n```\n\n3. run dec1.mjs to verify that lodestar fails to decode such file\n```\nchecking chunk type=255\nchecking chunk type=1\ngot uncompressed chunk..\nchecking chunk type=129\nfile:///../poc/dec1.mjs:74\n            throw new Error(\"Unsupported snappy chunk type\");\n```","references":[{"reference_url":"https://github.com/ChainSafe/lodestar","reference_id":"","reference_type":"","scores":[{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/ChainSafe/lodestar"},{"reference_url":"https://github.com/ChainSafe/lodestar/commit/18a0d681dbcc51fb2ac9456f31e91f4e31a18300","reference_id":"","reference_type":"","scores":[{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/ChainSafe/lodestar/commit/18a0d681dbcc51fb2ac9456f31e91f4e31a18300"},{"reference_url":"https://github.com/ChainSafe/lodestar/security/advisories/GHSA-53rv-hcvm-rpp9","reference_id":"","reference_type":"","scores":[{"value":"LOW","scoring_system":"generic_textual","scoring_elements":""}],"url":"https://github.com/ChainSafe/lodestar/security/advisories/GHSA-53rv-hcvm-rpp9"},{"reference_url":"https://github.com/advisories/GHSA-53rv-hcvm-rpp9","reference_id":"GHSA-53rv-hcvm-rpp9","reference_type":"","scores":[],"url":"https://github.com/advisories/GHSA-53rv-hcvm-rpp9"}],"fixed_packages":[{"url":"http://public2.vulnerablecode.io/api/packages/62888?format=json","purl":"pkg:npm/%40lodestar/reqresp@1.25.0","is_vulnerable":false,"affected_by_vulnerabilities":[],"resource_url":"http://public2.vulnerablecode.io/packages/pkg:npm/%2540lodestar/reqresp@1.25.0"}],"aliases":["GHSA-53rv-hcvm-rpp9"],"risk_score":null,"exploitability":null,"weighted_severity":null,"resource_url":"http://public2.vulnerablecode.io/vulnerabilities/VCID-9k1r-va4y-rbea"}],"fixing_vulnerabilities":[],"risk_score":null,"resource_url":"http://public2.vulnerablecode.io/packages/pkg:npm/%2540lodestar/reqresp@1.4.0-dev.230ece4d72"}