CVE-2021-32738: Stellar sdk Utils.readChallengeTx Does Not Verify The Vulnerability

MODERATE
Advisory Identifier: GHSA-6cgh-hjpw-q3gq
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CVSS 6.5
CWE-287 CWE-347
Published
Advisory Summary

CVE-2021-32738 is a MODERATE (CVSS 6.5) utils.readchallengetx does not verify the vulnerability (CWE-287: Improper Authentication) affecting Stellar sdk libraries in the npm ecosystem. The issue involves utils.readchallengetx does not verify the server account signature. Remediation is available by upgrading affected packages to version 8.2.3.

CVE-2021-32738 at a Glance

CVE Identifier CVE-2021-32738
GHSA Identifier GHSA-6cgh-hjpw-q3gq
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-287: Improper Authentication
Affected Product Stellar sdk
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2021-32738

To remediate this vulnerability, upgrade all affected Stellar sdk dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

stellar-sdk fixed: 8.2.3 
npm install stellar-sdk@8.2.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls stellar-sdk

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-32738, inspect your project dependencies using npm:

npm ls stellar-sdk

Analyze the terminal output to locate any version of Stellar sdk in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 8.2.3), your application is affected.

Note: The npm ls stellar-sdk command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-287: Improper Authentication, where when an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. In Stellar sdk, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The `Utils.readChallengeTx` function used in [SEP-10 Stellar Web Authentication](https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0010.md) states in its function documentation that it reads and validates the challenge transaction including verifying that the `serverAccountID` has signed the transaction. The function does not verify that the server has signed the transaction and has been fixed so that it does in v8.2.3. Applications that also used `Utils.verifyChallengeTxThreshold` or `Utils.verifyChallengeTxSigners` to verify the signatures including the server signature on the challenge transaction are unaffected as those functions verify the server signed the transaction. Applications calling `Utils.readChallengeTx` should update to v8.2.3 to ensure that the challenge transaction is completely valid and signed by the server creating the challenge transaction.

CVE-2021-32738 Affected Stellar sdk Versions

1 component(s)
Fixed Versions:
8.2.3
Product / Package Ecosystem Affected Versions Fixed Version
stellar-sdk
npm/stellar-sdk
npm
< 8.2.3
8.2.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/stellar/js-stellar-sdk/security/advisories/GHSA-6cgh-hjpw-q3gq
NVD — CVE-2021-32738 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-32738
Security Fix Commit FIX COMMIT
https://github.com/stellar/js-stellar-sdk/commit/6f0bb889c2d10b431ddd5f4a1bcdd519c80430b3
Stellar sdk Release RELEASE
https://github.com/stellar/js-stellar-sdk/releases/tag/v8.2.3

Frequently Asked Questions

What is CVE-2021-32738?
CVE-2021-32738 is a security vulnerability in Stellar sdk involving Utils.readChallengeTx does not verify the server account signature under CWE-287: Improper Authentication.
Which Stellar sdk versions are affected?
Affected versions include releases prior to 8.2.3 across affected packages: stellar-sdk.
What version fixes CVE-2021-32738?
Upgrading to 8.2.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is stellar-sdk affected?
Yes, stellar-sdk is affected in releases prior to 8.2.3. Upgrade your dependency to 8.2.3 or later.
What is the CVSS score of CVE-2021-32738?
CVE-2021-32738 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2021-32738?
CVE-2021-32738 is classified under CWE-287: Improper Authentication (When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.).
How can I check npm dependencies for CVE-2021-32738?
Run the dependency tree command: 'npm ls stellar-sdk'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6cgh-hjpw-q3gq",
  "modified" : "2021-07-02T18:25:08Z",
  "published" : "2021-07-02T19:20:33Z",
  "aliases" : [ "CVE-2021-32738" ],
  "summary" : "Utils.readChallengeTx does not verify the server account signature",
  "details" : "The `Utils.readChallengeTx` function used in [SEP-10 Stellar Web Authentication](https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0010.md) states in its function documentation that it reads and validates the challenge transaction including verifying that the `serverAccountID` has signed the transaction. The function does not verify that the server has signed the transaction and has been fixed so that it does in v8.2.3.\n\nApplications that also used `Utils.verifyChallengeTxThreshold` or `Utils.verifyChallengeTxSigners` to verify the signatures including the server signature on the challenge transaction are unaffected as those functions verify the server signed the transaction.\n\nApplications calling `Utils.readChallengeTx` should update to v8.2.3 to ensure that the challenge transaction is completely valid and signed by the server creating the challenge transaction.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "stellar-sdk"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.2.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/stellar/js-stellar-sdk/security/advisories/GHSA-6cgh-hjpw-q3gq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-32738"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/stellar/js-stellar-sdk/commit/6f0bb889c2d10b431ddd5f4a1bcdd519c80430b3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/stellar/js-stellar-sdk/releases/tag/v8.2.3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-287", "CWE-347" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-07-02T18:25:08Z",
    "nvd_published_at" : "2021-07-02T19:15:00Z"
  }
}