CVE-2024-55875 http4k has a potential XXE (XML External Entity Injection) vulnerability
Attackers can exploit XML parsing flaws in http4k to read local files, trigger SSRF, or cause denial of service via entity expansion.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-55875?
CVE-2024-55875 is a critical vulnerability in http4k, published on 12 Dec 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2024-55875?
2 open source packages ship an affected version, including org.http4k:http4k-format-xml.
| Package | Affected | Fixed in |
|---|---|---|
org.http4k:http4k-format-xml Maven | All versions | 6.50.0.0 |
org.http4k:http4k-format-xml Maven | All versions | 6.50.0.0 |
How do I fix CVE-2024-55875?
Upgrade org.http4k:http4k-format-xml to 6.50.0.0 or later.
Is CVE-2024-55875 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-55875 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-7mj5-hjjj-8rgw.