CVE-2024-55875
CriticalCVSS 9.8Exploitation Probability (EPSS)
Very high risk92th percentile - higher than 92% of all known CVEs
Summary
http4k is a functional toolkit for Kotlin HTTP applications. Prior to version 6.50.0.0, there was a potential XXE (XML External Entity Injection) vulnerability that could allow attackers to read local sensitive information on the server, trigger SSRF attacks, and even execute code under certain circumstances.
Risk Assessment
This vulnerability could lead to serious security breaches, including data disclosure and remote code execution, posing a threat to the integrity and confidentiality of the organization's systems.
Recommendation
It is recommended to upgrade to version 6.50.0.0 or later to mitigate this vulnerability by adding appropriate security settings in the XML parsing configuration.
Original NVD description (English source)
http4k is a functional toolkit for Kotlin HTTP applications. Prior to version 6.50.0.0, there is a potential XXE (XML External Entity Injection) vulnerability when http4k handling malicious XML contents within requests, which might allow attackers to read local sensitive information on server, trigger Server-side Request Forgery and even execute code under some circumstances. The original fix shipped in v5.41.0.0 / v4.50.0.0 closed the documented external-entity attack class (SSRF, local-file disclosure, code execution) by setting `ACCESS_EXTERNAL_DTD=""`, `ACCESS_EXTERNAL_SCHEMA=""`, and `isExpandEntityReferences=false` on the default `DocumentBuilderFactory`. A residual gap remained: the parser still accepted documents containing `<!DOCTYPE>` declarations even though external entity resolution was blocked. This left open billion-laughs-style internal entity expansion DoS attacks against any application using `Body.xml()` or `Document.asXmlDocument()` on untrusted XML. v6.50.0.0 closes this residual by adding `disallow-doctype-decl=true` and `FEATURE_SECURE_PROCESSING=true` to `defaultXmlParsingConfig`. Any document containing a `<!DOCTYPE>` is now rejected at parse time.