CVE-2024-32648: Vyper Vyper Default Functions Don't Respect Vulnerability

MODERATE
Advisory Identifier: GHSA-m2v9-w374-5hj9
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CVSS 5.3
CWE-667
Published
Advisory Summary

CVE-2024-32648 is a MODERATE (CVSS 5.3) vyper default functions don't respect vulnerability (CWE-667: Improper Locking) affecting Vyper libraries in the PyPI ecosystem. The issue involves vyper default functions don't respect nonreentrancy keys. Remediation is available by upgrading affected packages to version 0.3.0.

CVE-2024-32648 at a Glance

CVE Identifier CVE-2024-32648
GHSA Identifier GHSA-m2v9-w374-5hj9
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-667: Improper Locking
Affected Product Vyper
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.3

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

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

How to Fix CVE-2024-32648

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

vyper fixed: 0.3.0 
pip install vyper>=0.3.0
Verify Direct and Transitive Dependencies

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

pip show vyper

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2024-32648, inspect your installed packages using pip:

pip show vyper

Analyze the terminal output to locate any version of Vyper in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.0), your application is affected.

Note: The pip show vyper command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-667: Improper Locking, where the product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors. In Vyper, 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

### Summary Prior to v0.3.0, `__default__()` functions did not respect the `@nonreentrancy` decorator and the lock was not emitted. This is a known bug and was already visible in the issue tracker (https://github.com/vyperlang/vyper/issues/2455), but it is being re-issued as an advisory so that tools relying on the advisory publication list can incorporate it into their searches. A contract search was additionally performed and no vulnerable contracts were found in production. ### PoC ```vyper @external @payable @nonreentrant("default") def __default__(): pass ``` after codegen: ``` [seq, [if, [lt, calldatasize, 4], [goto, fallback]], [mstore, 28, [calldataload, 0]], [with, _func_sig, [mload, 0], seq], [seq_unchecked, [label, fallback], [seq, pass, # Line 5 pass, pass, # Line 4 stop]]], ``` ### Impact No vulnerable production contracts were found. Additionally, using a lock on a `default` function is a very sparsely used pattern. As such, the impact is `low`.

CVE-2024-32648 Affected Vyper Versions

1 component(s)
Fixed Versions:
0.3.0
Product / Package Ecosystem Affected Versions Fixed Version
vyper
pypi/vyper
PyPI
< 0.3.0
0.3.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/vyperlang/vyper/security/advisories/GHSA-m2v9-w374-5hj9
NVD — CVE-2024-32648 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-32648
Vyper Source Repository REPOSITORY
https://github.com/vyperlang/vyper/issues/2455
Security Fix Commit FIX COMMIT
https://github.com/vyperlang/vyper/commit/93287e5ac184b53b395c907d40701f721daf8177
Vyper Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2024-163.yaml
Vyper Source Repository REPOSITORY
https://github.com/vyperlang/vyper

Frequently Asked Questions

What is CVE-2024-32648?
CVE-2024-32648 is a security vulnerability in Vyper involving vyper default functions don't respect nonreentrancy keys under CWE-667: Improper Locking.
Which Vyper versions are affected?
Affected versions include releases prior to 0.3.0 across affected packages: vyper.
What version fixes CVE-2024-32648?
Upgrading to 0.3.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is vyper affected?
Yes, vyper is affected in releases prior to 0.3.0. Upgrade your dependency to 0.3.0 or later.
What is the CVSS score of CVE-2024-32648?
CVE-2024-32648 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2024-32648?
CVE-2024-32648 is classified under CWE-667: Improper Locking (The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.).
How can I check PyPI dependencies for CVE-2024-32648?
Run the dependency tree command: 'pip show vyper'. 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-m2v9-w374-5hj9",
  "modified" : "2025-01-14T16:37:11Z",
  "published" : "2024-04-25T19:50:35Z",
  "aliases" : [ "CVE-2024-32648" ],
  "summary" : "vyper default functions don't respect nonreentrancy keys",
  "details" : "### Summary\nPrior to v0.3.0, `__default__()` functions did not respect the `@nonreentrancy` decorator and the lock was not emitted. This is a known bug and was already visible in the issue tracker (https://github.com/vyperlang/vyper/issues/2455), but it is being re-issued as an advisory so that tools relying on the advisory publication list can incorporate it into their searches.\n\nA contract search was additionally performed and no vulnerable contracts were found in production.\n\n### PoC\n```vyper\n@external\n@payable\n@nonreentrant(\"default\")\ndef __default__():\n    pass\n```\n\nafter codegen:\n```\n[seq,\n  [if, [lt, calldatasize, 4], [goto, fallback]],\n  [mstore, 28, [calldataload, 0]],\n  [with, _func_sig, [mload, 0], seq],\n  [seq_unchecked,\n    [label, fallback],\n    [seq,\n      pass,\n      # Line 5\n      pass,\n      pass,\n      # Line 4\n      stop]]],\n```\n\n### Impact\nNo vulnerable production contracts were found. Additionally, using a lock on a `default` function is a very sparsely used pattern. As such, the impact is `low`.\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "vyper"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.2.16"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/vyperlang/vyper/security/advisories/GHSA-m2v9-w374-5hj9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-32648"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vyperlang/vyper/issues/2455"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vyperlang/vyper/commit/93287e5ac184b53b395c907d40701f721daf8177"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2024-163.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/vyperlang/vyper"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-667" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-25T19:50:35Z",
    "nvd_published_at" : "2024-04-25T18:15:09Z"
  }
}