CVE-2021-32742 — vapor
CRITICALCVE-2021-32742 is a critical-severity (CVSS 9.1) Deserialization of Untrusted Data vulnerability in github.com/vapor/vapor. A fix is available for github.com/vapor/vapor — see the affected versions and patch details below.
Untrusted data fed into `Data.init(base32Encoded:)` can result in exposing server memory and/or crash
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-2021-32742 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 378,156 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
github.com/vapor/vaporReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects SwiftURL packages — download data is not available via public APIs for these ecosystems.
Description
Impact
A bug in the Data.init(base32Encoded:) function opens up the potential for exposing server memory and/or crashing the server (Denial of Service) for applications where untrusted data can end up in said function. Vapor does not currently use this function itself so this only impact applications that use the impacted function directly or through other dependencies.
Patches
This issue has been patched in 4.47.2.
Workarounds
Use an alternative to Vapor's built-in Data.init(base32Encoded:).
For more information
If you have any questions or comments about this advisory:
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦SwiftURL | github.com/vapor/vapor | all versions | 4.47.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/vapor/vapor, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/vapor/vapor to 4.47.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-32742 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-2021-32742 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-32742. 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-2021-32742 in your dependencies?
O3 Security finds CVE-2021-32742 across SwiftURL dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.