GHSA-r6r4-5pr8-gjcp
MEDIUMVapor contains an integer overflow in URI leading to potential host spoofing
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.
Blast Radius
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
Vapor's vapor_urlparser_parse function uses uint16_t indexes when parsing a URI's components, which may cause integer overflows when parsing untrusted inputs.
This vulnerability does not affect Vapor directly but could impact applications relying on the URI type for validating user input.
The URI type is used in several places in Vapor. A developer may decide to use URI to represent a URL in their application (especially if that URL is then passed to the HTTP Client) and rely on its public properties and methods. However, URI may fail to properly parse a valid (albeit abnormally long) URL, due to string ranges being converted to 16-bit integers. An attacker may use this behaviour to trick the application into accepting a URL to an untrusted destination.
By padding the port number with zeros, an attacker can cause an integer overflow to occur when the URL authority is parsed and, as a result, spoof the host.
Impact
Users attempting to treat untrusted input as a URI are vulnerable to a host spoofing attack due to an integer overflow.
Workarounds
Validate user input before parsing as a URI or, if possible, use Foundation's URL and URLComponents utilities.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦SwiftURL | github.com/vapor/vapor | all versions | 4.90.0 |
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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/vapor/vapor to 4.90.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r6r4-5pr8-gjcp 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 pinpoints whether GHSA-r6r4-5pr8-gjcp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-r6r4-5pr8-gjcp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-r6r4-5pr8-gjcp in your dependencies?
O3 detects GHSA-r6r4-5pr8-gjcp across SwiftURL dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.