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TI-2023-22608 Aliases CVE-2023-42443GHSA-c647-pxm2-c52w

Vyper vulnerable to memory corruption in certain builtins utilizing `msize`

Priority LOW 39CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-787 and the CVSS impact.

Summary

Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). In version 0.3.9 and prior, under certain conditions, the memory used by the builtins `raw_call`, `create_from_blueprint` and `create_copy_of` can be corrupted. For `raw_call`, the argument buffer of the call can be corrupted, leading to incorrect `calldata` in the sub-context. For `create_from_blueprint` and `create_copy_of`, the buffer for the to-be-deployed bytecode can be corrupted, leading to deploying incorrect bytecode. Each builtin has conditions that must be fulfilled for the corruption to happen. For `raw_call`, the `data` argument of the builtin must be `msg.data` and the `value` or `gas` passed to the builtin must be some complex expression that results in writing to the memory. For `create_copy_of`, the `value` or `salt` passed to the builtin must be some complex expression that results in writing to the memory. For `create_from_blueprint`, either no constructor parameters should be passed to the builtin or `raw_args` should be set to True, and the `value` or `salt` passed to the builtin must be some complex expression that results in writing to the memory. As of time of publication, no patched version exists. The issue is still being investigated, and there might be other cases where the corruption might happen. When the builtin is being called from an `internal` function `F`, the issue is not present provided that the function calling `F` wrote to memory before calling `F`. As a workaround, the complex expressions that are being passed as kwargs to the builtin should be cached in memory prior to the call to the builtin.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00832 57th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed vyper (PyPI): 0.3.10

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
vyperlangvyperup to 0.3.9—No fix listedCNA
—vyper (PyPI)0.3.4 to before 0.3.100.3.10Patch availableGHSA-c647-pxm2-c52w
  • vyper Vendorvyperlang Affected up to 0.3.9 Fixed in — No fix listed CNA
  • vyper (PyPI) Vendor— Affected 0.3.4 to before 0.3.10 Fixed in 0.3.10 Patch available GHSA-c647-pxm2-c52w

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:python:*:*before 0.3.10Vulnerablevyperlang
  • cpe:2.3:a:vyperlang:vyper:*:*:*:*:*:python:*:* Versions before 0.3.10 Vulnerable ·vyperlang

Remediation

  • Fix · GHSA-c647-pxm2-c52w vyper (PyPI) Fixed in 0.3.10 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-42443
  2. 2026-10-03 Alias added: GHSA-c647-pxm2-c52w

References

  • TI-2024-16182 Vyper bounds check on built-in `slice()` function can be overflowed CVSS 3.1CRITICAL 9.8
  • TI-2024-14992 concat built-in can corrupt memory in vyper CVSS 3.1CRITICAL 9.8
  • TI-2024-16184 Vyper array negative index vulnerability CVSS 3.1CRITICAL 9.8
  • TI-2022-08657 Integer bounds error in Vyper CVSS 3.1CRITICAL 9.8
  • TI-2022-11796 Multiple evaluation of contract address in call in vyper CVSS 3.1HIGH 8.2
  • TI-2024-21531 vyper performs double eval of the argument of sqrt CVSS 3.1MEDIUM 5.3
See all 37 →

Sources