pysec - pysec-2025-31

PYSEC-2025-31

Vulnerability from pysec - Published: 2025-02-21 22:15 - Updated: 2025-04-09 17:27

Details

vyper is a Pythonic Smart Contract Language for the EVM. Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. This issue has been addressed in version 0.4.1 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Impacted products

Name	purl
vyper	pkg:pypi/vyper

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "vyper",
        "purl": "pkg:pypi/vyper"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.0b1",
        "0.1.0b10",
        "0.1.0b11",
        "0.1.0b12",
        "0.1.0b13",
        "0.1.0b14",
        "0.1.0b15",
        "0.1.0b16",
        "0.1.0b17",
        "0.1.0b2",
        "0.1.0b3",
        "0.1.0b4",
        "0.1.0b5",
        "0.1.0b6",
        "0.1.0b7",
        "0.1.0b8",
        "0.1.0b9",
        "0.2.1",
        "0.2.10",
        "0.2.11",
        "0.2.12",
        "0.2.13",
        "0.2.14",
        "0.2.15",
        "0.2.16",
        "0.2.2",
        "0.2.3",
        "0.2.4",
        "0.2.5",
        "0.2.6",
        "0.2.7",
        "0.2.8",
        "0.2.9",
        "0.3.0",
        "0.3.1",
        "0.3.10",
        "0.3.10rc1",
        "0.3.10rc2",
        "0.3.10rc3",
        "0.3.10rc4",
        "0.3.10rc5",
        "0.3.2",
        "0.3.3",
        "0.3.4",
        "0.3.5",
        "0.3.6",
        "0.3.7",
        "0.3.8",
        "0.3.9",
        "0.4.0",
        "0.4.0b1",
        "0.4.0b2",
        "0.4.0b3",
        "0.4.0b4",
        "0.4.0b5",
        "0.4.0b6",
        "0.4.0rc1",
        "0.4.0rc2",
        "0.4.0rc3",
        "0.4.0rc4",
        "0.4.0rc5",
        "0.4.0rc6",
        "0.4.1b1",
        "0.4.1b2",
        "0.4.1b3",
        "0.4.1b4",
        "0.4.1rc1",
        "0.4.1rc2",
        "0.4.1rc3"
      ]
    }
  ],
  "aliases": [
    "CVE-2025-27105",
    "GHSA-4w26-8p97-f4jp"
  ],
  "details": "vyper is a Pythonic Smart Contract Language for the EVM. Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. This issue has been addressed in version 0.4.1 and all users are advised to upgrade. There are no known workarounds for this vulnerability.",
  "id": "PYSEC-2025-31",
  "modified": "2025-04-09T17:27:28.116292+00:00",
  "published": "2025-02-21T22:15:13+00:00",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/vyperlang/vyper/security/advisories/GHSA-4w26-8p97-f4jp"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/vyperlang/vyper/security/advisories/GHSA-4w26-8p97-f4jp"
    }
  ]
}

CVE-2025-27105 (GCVE-0-2025-27105)

Vulnerability from cvelistv5 – Published: 2025-02-21 21:27 – Updated: 2025-02-22 15:37

Summary

Severity ?

2.3 (Low)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

CWE

CWE-787 - Out-of-bounds Write

Assigner

GitHub_M

References

URL

Tags

https://github.com/vyperlang/vyper/security/advis…

x_refsource_CONFIRM

Impacted products

	Vendor	Product	Version
	vyperlang	vyper	Affected: < 0.4.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.1,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "NONE",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2025-27105",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-02-22T15:36:50.306173Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-02-22T15:37:28.734Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "vyper",
          "vendor": "vyperlang",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.4.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "vyper is a Pythonic Smart Contract Language for the EVM. Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. This issue has been addressed in version 0.4.1 and all users are advised to upgrade. There are no known workarounds for this vulnerability."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 2.3,
            "baseSeverity": "LOW",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787: Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-02-21T21:27:28.056Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/vyperlang/vyper/security/advisories/GHSA-4w26-8p97-f4jp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/vyperlang/vyper/security/advisories/GHSA-4w26-8p97-f4jp"
        }
      ],
      "source": {
        "advisory": "GHSA-4w26-8p97-f4jp",
        "discovery": "UNKNOWN"
      },
      "title": "AugAssign evaluation order causing OOB write within the object in Vyper"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-27105",
    "datePublished": "2025-02-21T21:27:28.056Z",
    "dateReserved": "2025-02-18T16:44:48.766Z",
    "dateUpdated": "2025-02-22T15:37:28.734Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

GHSA-4W26-8P97-F4JP

Vulnerability from github – Published: 2025-02-21 22:43 – Updated: 2025-04-09 20:14

Summary

AugAssign evaluation order causing OOB write within the object in Vyper

Details

Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. In other words, the following code

def poc():
    a: DynArray[uint256, 2] = [1, 2]
    a[1] += a.pop()

is equivalent to:

def poc():
    a: DynArray[uint256, 2] = [1, 2]
    a[1] += a[len(a) - 1]
    a.pop()

rather than:

def poc():
    a: DynArray[uint256, 2] = [1, 2]
    s: uint256 = a[1]
    t: uint256 = a.pop()
    a[1] = s + t  # reverts due to oob access

Severity ?

2.3 (Low)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.4.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "vyper"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-27105"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-787"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-02-21T22:43:33Z",
    "nvd_published_at": "2025-02-21T22:15:13Z",
    "severity": "LOW"
  },
  "details": "Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. In other words, the following code\n\n```vyper\ndef poc():\n    a: DynArray[uint256, 2] = [1, 2]\n    a[1] += a.pop()\n```\n\nis equivalent to:\n```vyper\ndef poc():\n    a: DynArray[uint256, 2] = [1, 2]\n    a[1] += a[len(a) - 1]\n    a.pop()\n```\nrather than:\n```vyper\ndef poc():\n    a: DynArray[uint256, 2] = [1, 2]\n    s: uint256 = a[1]\n    t: uint256 = a.pop()\n    a[1] = s + t  # reverts due to oob access\n```",
  "id": "GHSA-4w26-8p97-f4jp",
  "modified": "2025-04-09T20:14:00Z",
  "published": "2025-02-21T22:43:33Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vyperlang/vyper/security/advisories/GHSA-4w26-8p97-f4jp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-27105"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2025-31.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/vyperlang/vyper"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "AugAssign evaluation order causing OOB write within the object in Vyper"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

PYSEC-2025-31

CVE-2025-27105 (GCVE-0-2025-27105)

GHSA-4W26-8P97-F4JP

Tags

Sightings

Nomenclature