CVE-2024-32647 vyper performs double eval of raw_args in create_from_blueprint

Medium 5.3 Published Updated

Vyper compiler double-evaluates arguments in create_from_blueprint, potentially allowing code execution if raw_args is enabled and args have side effects.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2024-32647?

CVE-2024-32647 is a medium-severity code injection vulnerability in vyperlang vyper, published on 25 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. In versions 0.3.10 and prior, using the `create_from_blueprint` builtin can result in a double eval vulnerability when `raw_args=True` and the `args` argument has side-effects. It can be seen that the `_build_create_IR` function of the `create_from_blueprint` builtin doesn't cache the mentioned `args` argument to the stack. As such, it can be evaluated multiple times (instead of retrieving the value from the stack). No vulnerable production contracts were found. Additionally, double evaluation of side-effects should be easily discoverable in client tests. As such, the impact is low. As of time of publication, no fixed versions exist.

Weakness: CWE-95

Which versions are affected by CVE-2024-32647?

3 open source packages ship an affected version, including vyper. It affects 1 product.

PackageAffectedFixed in
vyper PyPIAll versions0.4.0
vyper PyPIAll versions0.4.0
vyper PyPIAll versions0.4.0

Products include Vyperlang Vyper.

How do I fix CVE-2024-32647?

Upgrade vyper to 0.4.0 or later.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2024-32647 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-32647 exists.

Sources

Also known as GHSA-3whq-64q2-qfj6, PYSEC-2024-208.

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