CVE-2022-23653: B2 B2 Command Line Tool TOCTOU Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8wr4-2wm6-w3pr",
  "modified" : "2024-09-04T20:58:13Z",
  "published" : "2022-02-24T13:11:51Z",
  "aliases" : [ "CVE-2022-23653" ],
  "summary" : "B2 Command Line Tool TOCTOU application key disclosure ",
  "details" : "### Impact\n\nLinux and Mac releases of the B2 command-line tool version 3.2.0 and below contain a key disclosure vulnerability that, in certain conditions, can be exploited by local attackers through a time-of-check-time-of-use (TOCTOU) race condition.\n\nThe command line tool saves API keys (and bucket name-to-id mapping) in a local database file (`$XDG_CONFIG_HOME/b2/account_info`, `~/.b2_account_info` or a user-defined path) when `b2 authorize-account` is first run. This happens regardless of whether a valid key is provided or not. When first created, the file is world readable and is (typically a few milliseconds) later altered to be private to the user. If the directory is readable by a local attacker and the user did not yet run `b2 authorize-account` then during the brief period between file creation and permission modification, a local attacker can race to open the file and maintain a handle to it. This allows the local attacker to read the contents after the file after the sensitive information has been saved to it.\n\n### Remediation\n\nUsers that have not yet run `b2 authorize-account` should upgrade to B2 Command-Line Tool v3.2.1 before running it.\n\nUsers that have run `b2 authorize-account` are safe if at the time of the file creation no other local users had read access to the local configuration file.\n\nUsers that have run `b2 authorize-account` where the designated path could be opened by another local user should upgrade to B2 Command-Line Tool v3.2.1 and remove the database and regenerate all application keys. Note that `b2 clear-account` does not remove the database file and it should not be used to ensure that all open handles to the file are invalidated.\n\n### Workarounds\nIf B2 Command-Line Tool cannot be upgraded to v3.2.1 due to a dependency conflict, a binary release can be used instead. Alternatively a new version could be installed within a virtualenv, or the permissions can be changed to prevent local users from opening the database file.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [B2 Command-Line Tool](https://github.com/Backblaze/B2_Command_Line_Tool) mentioning the CVE id in the issue title\n* Email us at [security@backblaze.com](mailto:security@backblaze.com)\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "b2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.2.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Backblaze/B2_Command_Line_Tool/security/advisories/GHSA-8wr4-2wm6-w3pr"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2022-23653"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Backblaze/B2_Command_Line_Tool/commit/c74029f9f75065e8f7e3c3ec8e0a23fb8204feeb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Backblaze/B2_Command_Line_Tool"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/b2/PYSEC-2022-32.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-367" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-02-24T13:11:51Z",
    "nvd_published_at" : "2022-02-23T23:15:00Z"
  }
}