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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-32645 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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' |
Detection & 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-32645 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-32645. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-32645 in your dependencies?
O3 Security finds CVE-2024-32645 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.