CVE-2024-32645 — vyper
MEDIUMCVE-2024-32645 is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in vyper. A fix is available for vyper — see the affected versions and patch details below.
vyper performs incorrect topic logging in raw_log
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-32645.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
vyperReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Incorrect values can be logged when raw_log builtin is called with memory or storage arguments to be used as topics.
A contract search was performed and no vulnerable contracts were found in production. In particular, no uses of raw_log() were found at all in production; it is apparently not a well-known function.
Details
The build_IR function of the RawLog class fails to properly unwrap the variables provided as topics. Consequently, incorrect values are logged as topics.
PoC
x: bytes32
@external
def f():
self.x = 0x1234567890123456789012345678901234567890123456789012345678901234
raw_log([self.x], b"") # LOG1(offset:0x60, size:0x00, topic1:0x00)
y: bytes32 = 0x1234567890123456789012345678901234567890123456789012345678901234
raw_log([y], b"") # LOG1(offset:0x80, size:0x00, topic1:0x40)
Patches
Fixed in https://github.com/vyperlang/vyper/pull/3977.
Impact
Incorrect values can be logged which may result in unexpected behavior in client-side applications relying on these logs.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | vyper | all versions | 0.4.0pip install --upgrade 'vyper==0.4.0' |
Affected Products
vypervyperlangDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vyper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update vyper to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-32645 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2024-32645 in your dependencies?
Find it across PyPI, including transitive dependencies.