CVE-2023-30837: Vyper Vyper Vulnerable To Storage Allocator Vulnerability

HIGH
Advisory Identifier: GHSA-mgv8-gggw-mrg6
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CVSS 7.5
CWE-789
Published
Advisory Summary

CVE-2023-30837 is a HIGH (CVSS 7.5) vyper vulnerable to storage allocator vulnerability (CWE-789: Memory Allocation with Excessive Size Value) affecting Vyper libraries in the PyPI ecosystem. The issue involves vyper vulnerable to storage allocator overflow. Remediation is available by upgrading affected packages to version 0.3.8.

CVE-2023-30837 at a Glance

CVE Identifier CVE-2023-30837
GHSA Identifier GHSA-mgv8-gggw-mrg6
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-789: Memory Allocation with Excessive Size Value
Affected Product Vyper
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:H/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 High (I:H)
Availability None (A:N)

How to Fix CVE-2023-30837

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: 0.3.8 
pip install vyper>=0.3.8
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-2023-30837, 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 0.3.8), 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-789: Memory Allocation with Excessive Size Value, where the product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. 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

### Impact The storage allocator does not guard against allocation overflows. This can result in vulnerabilities like the following: ```vyper owner: public(address) take_up_some_space: public(uint256[10]) buffer: public(uint256[max_value(uint256)]) @external def initialize(): self.owner = msg.sender @external def foo(idx: uint256, data: uint256): self.buffer[idx] = data ``` Per @toonvanhove, "An attacker can overwrite the owner variable by calling this contract with calldata: `0x04bc52f8 fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff5 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff` (spaces inserted for readability) `0x04bc52f8` is the selector for `foo(uint256, uint256)`, and the last argument `fff...fff` is the new value for the owner variable." ### Patches patched in 0bb7203b584e771b23536ba065a6efda457161bb ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ ### References _Are there any links users can visit to find out more?_

CVE-2023-30837 Affected Vyper Versions

1 component(s)
Fixed Versions:
0.3.8
Product / Package Ecosystem Affected Versions Fixed Version
vyper
pypi/vyper
PyPI
< 0.3.8
0.3.8

References

GitHub Advisory / Wiki ADVISORY
https://github.com/vyperlang/vyper/security/advisories/GHSA-mgv8-gggw-mrg6
NVD — CVE-2023-30837 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-30837
Security Fix Commit FIX COMMIT
https://github.com/vyperlang/vyper/commit/0bb7203b584e771b23536ba065a6efda457161bb
Vyper Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-76.yaml
Vyper Source Repository REPOSITORY
https://github.com/vyperlang/vyper

Frequently Asked Questions

What is CVE-2023-30837?
CVE-2023-30837 is a security vulnerability in Vyper involving vyper vulnerable to storage allocator overflow under CWE-789: Memory Allocation with Excessive Size Value.
Which Vyper versions are affected?
Affected versions include releases prior to 0.3.8 across affected packages: vyper.
What version fixes CVE-2023-30837?
Upgrading to 0.3.8 (or the latest patched release for your respective branch) resolves the vulnerability.
Is vyper affected?
Yes, vyper is affected in releases prior to 0.3.8. Upgrade your dependency to 0.3.8 or later.
What is the CVSS score of CVE-2023-30837?
CVE-2023-30837 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2023-30837?
CVE-2023-30837 is classified under CWE-789: Memory Allocation with Excessive Size Value (The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.).
How can I check PyPI dependencies for CVE-2023-30837?
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-mgv8-gggw-mrg6",
  "modified" : "2024-11-19T16:31:53Z",
  "published" : "2023-05-05T22:22:23Z",
  "aliases" : [ "CVE-2023-30837" ],
  "summary" : "vyper vulnerable to storage allocator overflow",
  "details" : "### Impact\nThe storage allocator does not guard against allocation overflows. This can result in vulnerabilities like the following:\n```vyper\nowner: public(address)\ntake_up_some_space: public(uint256[10])\nbuffer: public(uint256[max_value(uint256)])\n\n@external\ndef initialize():\n    self.owner = msg.sender\n\n@external\ndef foo(idx: uint256, data: uint256):\n    self.buffer[idx] = data\n```\nPer @toonvanhove, \"An attacker can overwrite the owner variable by calling this contract with calldata: `0x04bc52f8 fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff5 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff` (spaces inserted for readability)\n`0x04bc52f8` is the selector for `foo(uint256, uint256)`, and the last argument `fff...fff` is the new value for the owner variable.\"\n\n### Patches\npatched in 0bb7203b584e771b23536ba065a6efda457161bb\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\n### References\n_Are there any links users can visit to find out more?_\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "vyper"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/vyperlang/vyper/security/advisories/GHSA-mgv8-gggw-mrg6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-30837"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vyperlang/vyper/commit/0bb7203b584e771b23536ba065a6efda457161bb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-76.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/vyperlang/vyper"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-789" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-05-05T22:22:23Z",
    "nvd_published_at" : "2023-05-08T17:15:12Z"
  }
}