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GHSA-mgv8-gggw-mrg6 CVE-2023-30837 PYSEC-2023-76

vyper vulnerable to storage allocator overflow

High PyPI
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.70%
Chance of exploitation in the next 30 days. Higher than 53.09% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-789 Memory Allocation with Excessive Size Value
Fix
0.3.8
Upgrade vyper to this version or later

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?

Affected versions

PyPI

PackageVulnerableFixed in
vyper
< 0.3.8
0.3.8
vyper
< 0.3.8
0.3.8

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

vyper PyPI → 0.3.8

pip
pip install --upgrade "vyper>=0.3.8"
poetry
poetry add "vyper>=0.3.8"
uv
uv add "vyper>=0.3.8"

Severity breakdown

CVSS 4.0 0.0

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

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
High
Availability (vulnerable system)
None
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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

Weakness

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 to prevent it
  • Implementation, Architecture and Design: Perform adequate input validation against any value that influences the amount of memory that is allocated. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.
  • Operation: Run your program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.

References

Advisories

Packages

Other links

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-2r3x-4mrv-mcxf
Vyper: Memory corruption using function calls within tuples / nested calls
Medium Also affects vyper
GHSA-4v7v-gqf9-ww2g
Vyper: Call stack corruption when passing complex type containing non-base type members as argument
Medium Also affects vyper
GHSA-vg88-3v92-rjx2
Vyper: Return inside for loop more than 1 level deep
Low Also affects vyper
GHSA-3vcg-j39x-cwfm
Vyper's `slice()` may elide side-effects when output length is 0
Low Also affects vyper
GHSA-qhr6-mgqr-mchm
Vyper's `concat()` builtin may elide side-effects for zero-length arguments
Low Also affects vyper
GHSA-h33q-mhmp-8p67
Vyper has a double eval in For List Iter
High Also affects vyper
GHSA-4w26-8p97-f4jp
AugAssign evaluation order causing OOB write within the object in Vyper
Critical Also affects vyper
GHSA-2p94-8669-xg86
Vyper's sqrt doesn't define rounding behavior
High Also affects vyper
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