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vyper vulnerable to storage allocator overflow

High severity GitHub Reviewed Published May 5, 2023 in vyperlang/vyper • Updated Nov 12, 2023

Package

pip vyper (pip)

Affected versions

< 0.3.8

Patched versions

0.3.8

Description

Impact

The storage allocator does not guard against allocation overflows. This can result in vulnerabilities like the following:

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?

References

@charles-cooper charles-cooper published to vyperlang/vyper May 5, 2023
Published to the GitHub Advisory Database May 5, 2023
Reviewed May 5, 2023
Published by the National Vulnerability Database May 8, 2023
Last updated Nov 12, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS score

0.074%
(33rd percentile)

Weaknesses

CVE ID

CVE-2023-30837

GHSA ID

GHSA-mgv8-gggw-mrg6

Source code

Credits

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