MEDIUM CVSS 5.3
Published: 2025-03-12

CVE-2025-29904

jetbrains ktor Security Advisory (CVE-2025-29904)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-29904 impacting jetbrains ktor. Evaluated with CVSS Base Score of 5.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
In JetBrains Ktor before 3.1.1 an HTTP Request Smuggling was possible

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product jetbrains / ktor
Affected Versions *
Weakness Enumeration CWE-444

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2025-29904 impacting jetbrains ktor.

⚡ Nuclei Detection Template (YAML) cve-2025-29904.yaml
id: cve-2025-29904

info:
  name: jetbrains ktor - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2025-29904 affecting jetbrains ktor.
    Evaluation: In JetBrains Ktor before 3.1.1 an HTTP Request Smuggling was possible...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-29904
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
    cvss-score: 5.3
    cve-id: CVE-2025-29904
    cwe-id: CWE-444
  tags: cve,cve-2025-29904,jetbrains,ktor,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "ktor"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-29904.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-29904
# Target: jetbrains ktor | CVSS: 5.3 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-29904 (jetbrains ktor)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against jetbrains ktor scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2025-29904.sh
# Recommended Remediation & Patching Commands for CVE-2025-29904
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install ktor 2>/dev/null || \
sudo dnf upgrade ktor 2>/dev/null || \
sudo yum update ktor

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i ktor 2>/dev/null || rpm -qa | grep -i ktor

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2025-29904 in jetbrains ktor?

Review vendor-specific security notices and update jetbrains ktor packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2025-29904?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2025-29904?

CVE-2025-29904 is classified with a CVSS 3.1 Base Score of 5.3 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.3
MEDIUM SEVERITY
CVE ID CVE-2025-29904
Weakness CWE-444
Vendor jetbrains
Product ktor
Published 2025-03-12
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N