Vulnerability Analysis

CVE-2026-48282: Adobe ColdFusion RDS Path Traversal Enables Unauthenticated RCE — Patch Immediately

Executive Summary

CVE-2026-48282 is a maximum-severity (CVSS 10.0) path traversal vulnerability in Adobe ColdFusion's Remote Development Services (RDS) FILEIO handler that allows unauthenticated remote attackers to write arbitrary files anywhere on the server file system — including the web root — resulting in full unauthenticated Remote Code Execution (RCE). Patched by Adobe on June 30, 2026 as part of bulletin APSB26-68, active exploitation was detected within two hours of public disclosure. Any internet-facing ColdFusion instance running version 2025 Update 9 or earlier, or 2023 Update 20 or earlier, should be considered fully compromised until patched.

1. What Is This Vulnerability?

Adobe ColdFusion includes a Remote Development Services (RDS) subsystem designed to support IDE integrations and remote file management operations. The RDS FILEIO handler accepts remote procedure call (RPC) requests to perform file system operations — reads, writes, renames, deletes — on the ColdFusion server.

The flaw is that the FILEIO handler processes user-supplied file paths using getFile(path) without performing path canonicalization or verifying that the resolved path stays within an authorized directory boundary. Attackers supply path traversal sequences (e.g., ../../) in the file path argument of a raw RDS RPC request, escaping the intended working directory and reaching any location the ColdFusion service account can write to — including the web root.

Attack Vector

The attack is delivered via a crafted HTTP POST to /CFIDE/main/ide.cfm?ACTION=FILEIO:

POST /CFIDE/main/ide.cfm?ACTION=FILEIO HTTP/1.1
Host: target.example.com
Content-Type: application/octet-stream
Content-Length: [length]

[RDS RPC binary payload]
WRITE
../../wwwroot/shell.cfm
<cfexecute name="cmd.exe" arguments="/c #url.cmd#" variable="output" /><cfoutput>#output#</cfoutput>
  • No authentication is required.
  • No URL encoding is required — traversal sequences are passed as literal bytes in the binary body.
  • The Content-Type: application/octet-stream header prevents proxies from inspecting or modifying the payload.

Once a web shell is written to the web root, the attacker accesses it directly to execute arbitrary OS commands under the ColdFusion service account.

Real-World Impact

Active exploitation was confirmed by vulnerability intelligence platform KEVIntel within two hours of Adobe's public disclosure on June 30, 2026. The initial attack recorded in the wild attempted to read C:\Windows\win.ini — a classic file read probe used to confirm exploitation before deploying persistent payloads. SecurityWeek and Help Net Security reported continued exploitation throughout the first week of July 2026. Adobe assigned its highest Priority Rating 1 to APSB26-68, reserved for flaws with confirmed or imminent active exploitation.

2. Who Is Affected?

Product Affected Versions Fixed Version
Adobe ColdFusion 2025 Update 9 and earlier Update 10
Adobe ColdFusion 2023 Update 20 and earlier Update 21
Adobe ColdFusion 2021 All versions End of life — no patch

All supported operating systems are affected (Windows, Linux, macOS). The vulnerability is unauthenticated and network-reachable, so any ColdFusion instance accessible from the internet or from an untrusted network segment is at critical risk. Instances with RDS disabled are not vulnerable to this specific attack vector; however, RDS is enabled by default in many installations.

APSB26-68 also includes six additional CVSS 10.0 flaws in ColdFusion and Adobe Campaign Classic (CVE-2026-48276, -48277, -48281, -48283, -48286, -48313, -48315, -48316), making this the highest-density maximum-severity bulletin Adobe has ever released. All should be treated as equivalently urgent.

3. How to Detect It (Testing)

Manual Testing Steps

Step 1: Check the ColdFusion version

# On Linux ColdFusion host:
cat /opt/coldfusion/cfusion/lib/version.properties

# On Windows:
type "C:\ColdFusion2025\cfusion\lib\version.properties"

Look for coldfusion.product.version and coldfusion.product.hotfix. If the update number is 9 or lower (2025 series) or 20 or lower (2023 series), the system is vulnerable.

Step 2: Test RDS accessibility

curl -sk -o /dev/null -w "%{http_code}" \
  "https://TARGET/CFIDE/main/ide.cfm?ACTION=FILEIO"

A 200 or 500 response (rather than 404) indicates the RDS endpoint is exposed.

Step 3: Attempt a benign file-read probe Use a security scanner or Burp Suite to send a crafted RDS RPC request targeting a known file (e.g., ../../../etc/hostname on Linux). A successful read of the file contents confirms exploitability. Only perform this test on systems you own or have written authorization to test.

Automated Scanning

Nuclei (recommended)

nuclei -u https://TARGET -t cves/2026/CVE-2026-48282.yaml -severity critical

Community-contributed Nuclei templates for CVE-2026-48282 began appearing on GitHub within 24 hours of disclosure.

Nessus / Tenable

  • Plugin ID for CVE-2026-48282 was included in Tenable feed updates released July 2–3, 2026.
  • Run a credentialed scan with "Adobe ColdFusion" in scope.

Shodan / Censys (external exposure check)

shodan search "ColdFusion" port:443,80 country:US

Use this to confirm whether your ColdFusion instance is internet-facing before testing.

Code Review Checklist

  • Confirm RDS is disabled in neo-security.xml (rds.enabled=false) if IDE integration is not required
  • Verify ColdFusion service runs under a least-privilege account (not Local System or root)
  • Check that the web root is write-protected from the ColdFusion service account
  • Review web access logs for POST /CFIDE/main/ide.cfm?ACTION=FILEIO entries
  • Scan for unexpected .cfm files in the web root that were recently created

4. How to Fix It (Mitigation)

Step-by-Step Remediation

  1. Apply the official patch immediately. Adobe released fixes on June 30, 2026 with Priority Rating 1 (patch within 72 hours):

    • ColdFusion 2025: apply Update 10
    • ColdFusion 2023: apply Update 21
    • ColdFusion 2021: End of life — migrate to a supported version

  2. Download the update from Adobe:

  3. Disable RDS if not in use (immediate compensating control before patching): Edit {cf_root}/cfusion/lib/neo-security.xml:

    <!-- Set RDS to disabled -->
<var name='rds.enabled'><boolean value='false'/></var>

    Restart the ColdFusion service after the change.

  4. Block RDS endpoints at the web server / WAF layer:

    # Nginx — block RDS endpoint
location ~* /CFIDE/main/ide\.cfm {
    deny all;
    return 403;
}

    # Apache — block RDS endpoint
<LocationMatch "/CFIDE/main/ide\.cfm">
    Require all denied
</LocationMatch>

  5. Restrict file system permissions. The ColdFusion service account should have read-only access to the web root and no write permissions outside of designated upload directories.

  6. Scan for indicators of compromise (IoC) before declaring the system clean (see Section 5).

Configuration Hardening

After patching, harden the ColdFusion deployment to reduce attack surface:

  • Disable RDS in production. RDS is an IDE development feature and should never be exposed on production servers.
  • Lock down CFIDE. The entire /CFIDE/ directory should be access-controlled (IP allowlist or auth) or blocked at the web server layer — it contains administrative interfaces beyond just RDS.
  • Run ColdFusion as a restricted service account (not Local System / root).
  • Enable ColdFusion Sandbox Security to restrict what file paths ColdFusion can access.
  • Use a WAF with Adobe ColdFusion-specific rules (AWS WAF Managed Rules, Cloudflare OWASP, ModSecurity CRS).

5. How to Test the Fix (Validation)

Regression Test Scenarios

  • Scenario A: Attempt the path traversal probe against the patched server — the server should return a 400 or 403, not process the request.
  • Scenario B: Verify that the RDS endpoint returns 403 if it was blocked at the web server layer.
  • Scenario C: Confirm ColdFusion application functionality is intact (application login, page rendering, file uploads via legitimate channels).

Security Test Cases

Test Case 1: Verify path traversal is blocked

  • Precondition: ColdFusion 2023 Update 21 or 2025 Update 10 applied
  • Steps: Send POST /CFIDE/main/ide.cfm?ACTION=FILEIO with a traversal payload targeting an out-of-scope file
  • Expected Result: Server returns HTTP 400/403; no file written; no successful read of target file

Test Case 2: Confirm no web shell was dropped

# Scan for recently created .cfm files in the web root
find /opt/coldfusion/cfusion/wwwroot -name "*.cfm" -newer /opt/coldfusion/cfusion/lib/version.properties

Any unexpected .cfm file warrants immediate incident investigation.

Test Case 3: Verify RDS disabled state persists after restart

grep -i 'rds.enabled' /opt/coldfusion/cfusion/lib/neo-security.xml

Confirm value='false' is present.

Automated Tests

import requests

def test_cve_2026_48282_patched(target_url):
    """Verify CVE-2026-48282 path traversal is no longer exploitable."""
    endpoint = f"{target_url}/CFIDE/main/ide.cfm?ACTION=FILEIO"
    # Minimal traversal probe — does not write any file
    probe_payload = b"\x00\x00READ\x00../../etc/hostname"
    headers = {"Content-Type": "application/octet-stream"}
    
    try:
        resp = requests.post(endpoint, data=probe_payload, headers=headers,
                             timeout=10, verify=False)
        if resp.status_code in (400, 403, 404):
            print(f"[PASS] {target_url} — RDS endpoint blocked or rejected traversal payload")
        elif resp.status_code == 200 and "root" in resp.text.lower():
            print(f"[FAIL] {target_url} — Server appears VULNERABLE (file read succeeded)")
        else:
            print(f"[WARN] {target_url} — Ambiguous response ({resp.status_code}), manual review needed")
    except requests.exceptions.ConnectionError:
        print(f"[INFO] {target_url} — Host unreachable or endpoint offline")

# Usage:
test_cve_2026_48282_patched("https://your-coldfusion-server.example.com")

6. Prevention & Hardening

Best Practices

  • Patch cadence discipline. Adobe assigned Priority Rating 1 to APSB26-68 — these bulletins require patching within 72 hours. Establish automated patch notifications from Adobe's security bulletin RSS feed.
  • Disable development features in production. RDS, ColdFusion Administrator over the public internet, and debugging interfaces should all be disabled or IP-restricted on production deployments. Development features are perennial sources of critical ColdFusion vulnerabilities.
  • Network segmentation. ColdFusion servers should not be directly internet-facing where possible. Place them behind a reverse proxy or API gateway, limit inbound connections to expected application traffic, and restrict outbound connections to required destinations only.
  • Regular vulnerability scanning. Run authenticated scans against ColdFusion instances weekly. Include ColdFusion in your patch management pipeline rather than treating it as a "set and forget" application tier.
  • Web Application Firewall. Deploy a WAF with OWASP CRS rules and ColdFusion-specific virtual patches for interim protection between vulnerability disclosure and patch deployment.
  • File integrity monitoring. Monitor the ColdFusion web root for unexpected file creation or modification. Alert on any new .cfm or .jsp file appearing outside of deployment pipelines.

Monitoring & Detection

Watch for these indicators in web server and ColdFusion logs:

# Suspicious RDS FILEIO requests
POST /CFIDE/main/ide.cfm?ACTION=FILEIO — any source, any time in production

# Path traversal sequences in request bodies (may appear in access logs)
../  ..\  %2e%2e%2f  %252e%252e

# Web shell access patterns — unexpected .cfm file accessed that wasn't deployed
GET /CFIDE/[randomname].cfm
GET /[webroot]/[randomname].cfm

# Signs of post-exploitation (ColdFusion process spawning unexpected children)
coldfusion.exe / java → cmd.exe / powershell.exe / /bin/bash

SIEM detection rule (Splunk):

index=weblogs sourcetype=access_combined
  uri_path="/CFIDE/main/ide.cfm" method=POST
| eval traversal=if(match(request_body, "\.\./|\.\.\\\\"), "YES", "NO")
| where traversal="YES"
| table _time, src_ip, uri_path, status, traversal
| sort -_time

References

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