CVE-2023-45612Public exploitNetwork attack vector

File disclosure via external entity resolution

Published Oct 9, 2023 · Updated Sep 19, 2024

XXE in Ktor ContentNegotiation before 2.3.5 allows remote attackers to read server-accessible files through crafted XML requests. Its default XML converter accepts DTD declarations and resolves external entity URIs while deserializing request bodies. Exposure requires an application to install ContentNegotiation with XML and route attacker-controlled XML into deserialization; disclosure is limited to resources reachable by the server process.

CVSS severity8.6
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

XXE in Ktor ContentNegotiation before 2.3.5 allows remote attackers to read server-accessible files through crafted XML requests. Its default XML converter accepts DTD declarations and resolves external entity URIs while deserializing request bodies. Exposure requires an application to install ContentNegotiation with XML and route attacker-controlled XML into deserialization; disclosure is limited to resources reachable by the server process.

The record

CVE
CVE-2023-45612
Published
Oct 9, 2023
Updated
Sep 19, 2024
Vendor
JetBrains
Product
Ktor
Classifications
CWE-611, CAPEC-221, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 19, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.3.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

JetBrains · Ktorversion=0 <2.3.5

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.6JetBrains s.r.o.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
CAPEC-221Data Serialization External Entities Blowup
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo