GHSA-MGC4-WQV7-4PXM

SwiftNIO vulnerable to HTTP request smuggling using malformed Transfer-Encoding header

Workarounds

No workaround is available, users must upgrade.

References

https://nodejs.org/en/blog/vulnerability/february-2020-security-releases/#http-request-smuggling-using-malformed-transfer-encoding-header-critical-cve-2019-15605

Affected SwiftNIO systems are vulnerable to request smuggling attacks, in which they parse a given HTTP message differently from other network parties, potentially seeing a different number of requests than other servers. This can lead to failures of authentication, routing, and other issues.

This vulnerability can be found in the bundled copy of the Node.JS HTTP parser used in the NIOHTTP1 module.

GHSA-MGC4-WQV7-4PXM has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.14.2, 2.13.1); upgrading removes the vulnerable code path.

Kodem intelligence

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1. What is GHSA-MGC4-WQV7-4PXM? GHSA-MGC4-WQV7-4PXM is a critical-severity security vulnerability in github.com/apple/swift-nio (swift), affecting versions >= 1.0.0, < 1.14.2. It is fixed in 1.14.2, 2.13.1.
2. How severe is GHSA-MGC4-WQV7-4PXM? GHSA-MGC4-WQV7-4PXM has a CVSS score of 9.8 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/apple/swift-nio are affected by GHSA-MGC4-WQV7-4PXM? github.com/apple/swift-nio (swift) versions >= 1.0.0, < 1.14.2 is affected.
4. Is there a fix for GHSA-MGC4-WQV7-4PXM? Yes. GHSA-MGC4-WQV7-4PXM is fixed in 1.14.2, 2.13.1. Upgrade to this version or later.
5. Is GHSA-MGC4-WQV7-4PXM exploitable, and should I be worried? Whether GHSA-MGC4-WQV7-4PXM is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether GHSA-MGC4-WQV7-4PXM is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix GHSA-MGC4-WQV7-4PXM?
   • Upgrade github.com/apple/swift-nio to 1.14.2 or later
   • Upgrade github.com/apple/swift-nio to 2.13.1 or later

Other vulnerabilities in github.com/apple/swift-nio