GHSA-3F99-HVG4-QJWJ高危已审查

Insecure random number generation in keypair

OSV 1.4.0 · github-reviewed · 修改于 2021-10-12 02:36

发布时间

2021-10-12 01:09

GitHub 审查时间

2021-10-12 01:06

NVD 发布时间

2021-10-12 01:15

源文件

advisories/github-reviewed/2021/10/GHSA-3f99-hvg4-qjwj/GHSA-3f99-hvg4-qjwj.json

公告说明

Description and Impact

A bug in the pseudo-random number generator used by keypair versions up to and including 1.0.3 could allow for weak RSA key generation. This could enable an attacker to decrypt confidential messages or gain authorized access to an account belonging to the victim. We recommend replacing any RSA keys that were generated using keypair version 1.0.3 or earlier.

Fix

The bug in the pseudo-random number generator is fixed in commit 9596418.
If the crypto module is available, it is used instead of the pseudo-random number generator. Also fixed in 9596418

Additional Details

The specific line with the flaw is:

b.putByte(String.fromCharCode(next & 0xFF))

The definition of putByte is

util.ByteBuffer.prototype.putByte = function(b) {
  this.data += String.fromCharCode(b);
};

Simplified, this is String.fromCharCode(String.fromCharCode(next & 0xFF)). This results in most of the buffer containing zeros. An example generated buffer:

(Note: truncated for brevity)

\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00
\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00
\x00\x00\x00\x00\x04\x00\x00\x00....\x00\x00\x00\x00\x00\x00\x00\x00\x00
\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00
\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00

标识信息

别名 / CVE

CVE-2021-41117

CWE

CWE-335

软件生态

npm

扩展资料

暂无扩展资料。

CVSS 评分

CVSS_V3

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

原始 OSV JSON

{
  "id": "GHSA-3f99-hvg4-qjwj",
  "aliases": [
    "CVE-2021-41117"
  ],
  "details": "## Description and Impact\n\nA bug in the pseudo-random number generator used by [keypair](https://github.com/juliangruber/keypair) versions up to and including 1.0.3 could allow for weak RSA key generation. This could enable an attacker to decrypt confidential messages or gain authorized access to an account belonging to the victim. We recommend replacing any RSA keys that were generated using keypair version 1.0.3 or earlier.\n\n## Fix\n\n* The [bug](https://github.com/juliangruber/keypair/blob/87c62f255baa12c1ec4f98a91600f82af80be6db/index.js#L1008) in the pseudo-random number generator is fixed in commit [`9596418`](https://github.com/juliangruber/keypair/commit/9596418d3363d3e757676c0b6a8f2d35a9d1cb18).\n* If the crypto module is available, it is used instead of the pseudo-random number generator. Also fixed in [`9596418`](https://github.com/juliangruber/keypair/commit/9596418d3363d3e757676c0b6a8f2d35a9d1cb18)\n\n## Additional Details\n\nThe specific [line](https://github.com/juliangruber/keypair/blob/87c62f255baa12c1ec4f98a91600f82af80be6db/index.js#L1008) with the flaw is:\n\n```javascript\nb.putByte(String.fromCharCode(next & 0xFF))\n```\n\nThe [definition](https://github.com/juliangruber/keypair/blob/87c62f255baa12c1ec4f98a91600f82af80be6db/index.js#L350-L352) of `putByte` is \n\n```javascript\nutil.ByteBuffer.prototype.putByte = function(b) {\n  this.data += String.fromCharCode(b);\n};\n```\n\nSimplified, this is `String.fromCharCode(String.fromCharCode(next & 0xFF))`. This results in most of the buffer containing zeros. An example generated buffer:\n\n(Note: truncated for brevity)\n\n```\n\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\n\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\n\\x00\\x00\\x00\\x00\\x04\\x00\\x00\\x00....\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\n\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\n\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\n```\n\nSince it is masking with 0xFF, approximately 97% of the bytes are converted to zeros. The impact is that each byte in the RNG seed has a 97% chance of being 0 due to incorrect conversion.\n\n## Credit\n\nThis issue was reported to GitHub Security Lab by Ross Wheeler of Axosoft. It was discovered by Axosoft engineer Dan Suceava, who noticed that [keypair](https://github.com/juliangruber/keypair) was regularly generating duplicate RSA keys. GitHub security engineer [@vcsjones (Kevin Jones)](https://github.com/vcsjones) independently investigated the problem and identified the cause and source code location of the bug.",
  "summary": "Insecure random number generation in keypair",
  "affected": [
    {
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.4"
            }
          ]
        }
      ],
      "package": {
        "name": "keypair",
        "ecosystem": "npm"
      }
    }
  ],
  "modified": "2021-10-11T18:36:36Z",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N"
    }
  ],
  "published": "2021-10-11T17:09:05Z",
  "references": [
    {
      "url": "https://github.com/juliangruber/keypair/security/advisories/GHSA-3f99-hvg4-qjwj",
      "type": "WEB"
    },
    {
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-41117",
      "type": "ADVISORY"
    },
    {
      "url": "https://github.com/juliangruber/keypair/commit/9596418d3363d3e757676c0b6a8f2d35a9d1cb18",
      "type": "WEB"
    },
    {
      "url": "https://github.com/juliangruber/keypair",
      "type": "PACKAGE"
    },
    {
      "url": "https://github.com/juliangruber/keypair/releases/tag/v1.0.4",
      "type": "WEB"
    },
    {
      "url": "https://securitylab.github.com/advisories/GHSL-2021-1012-keypair",
      "type": "ADVISORY"
    }
  ],
  "schema_version": "1.4.0",
  "database_specific": {
    "cwe_ids": [
      "CWE-335"
    ],
    "severity": "HIGH",
    "github_reviewed": true,
    "nvd_published_at": "2021-10-11T17:15:00Z",
    "github_reviewed_at": "2021-10-11T17:06:03Z"
  }
}