CVE-2024-41949: Biscuit auth Biscuit-auth Vulnerable To Public Key Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-p9w4-585h-g3c7",
  "modified" : "2024-08-05T21:14:26Z",
  "published" : "2024-07-31T21:15:41Z",
  "aliases" : [ "CVE-2024-41949" ],
  "summary" : "biscuit-auth vulnerable to public key confusion in third party block",
  "details" : "Third-party blocks can be generated without transferring the whole token to the third-party authority. Instead, a `ThirdPartyBlock` request can be sent, providing only the necessary info to generate a third-party block and to sign it:\n\n- the public key of the previous block (used in the signature)\n- the public keys part of the token symbol table (for public key interning in datalog expressions)\n\nA third-part block request forged by a malicious user can trick the third-party authority into generating datalog trusting the wrong keypair.\n\nConsider the following example (nominal case)\n\n- Authority `A` emits the following token: `check if thirdparty(\"b\") trusting ${pubkeyB}`\n- The well-behaving holder then generates a third-party block request based on the token and sends it to third-party authority `B`\n- Third-party `B` generates the following third-party block `thirdparty(\"b\"); check if thirdparty(\"c\") trusting ${pubkeyC}`\n- The token holder now must obtain a third-party block from third party `C` to be able to use the token\n\nNow, with a malicious user:\n- Authority `A` emits the following token: `check if thirdparty(\"b\") trusting ${pubkeyB}`\n- The holder then attenuates the token with the following third party block `thirdparty(\"c\")`, signed with a keypair `pubkeyD, privkeyD)` they generate\n- The holder then generates a third-party block request based on this token, but alter the `ThirdPartyBlockRequest` `publicKeys` field and replace `pubkeyD` with `pubkeyC`\n- Third-party `B` generates the following third-party block `thirdparty(\"b\"); check if thirdparty(\"c\") trusting ${pubkeyC}`\n- Due to the altered symbol table, the actual meaning of the block is `thirdparty(\"b\"); check if thirdparty(\"c\") trusting ${pubkeyD}`\n- The attacker can now use the token without obtaining a third-party block from `C`.\n\n### Impact\n\nTokens with third-party blocks containing `trusted` annotations generated through a third party block request\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "biscuit-auth"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "5.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/biscuit-auth/biscuit-rust/security/advisories/GHSA-p9w4-585h-g3c7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/biscuit-auth/biscuit/security/advisories/GHSA-rgqv-mwc3-c78m"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-41949"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/biscuit-auth/biscuit-rust"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-269" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-07-31T21:15:41Z",
    "nvd_published_at" : "2024-08-01T22:15:28Z"
  }
}