Comprehensive Technical Analysis of EUVD-2026-2004 (CVE-2026-22783)

Vulnerability in DFIR-IRIS Web Platform (Arbitrary File Deletion via Mass Assignment & Path Trust)

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1. Vulnerability Assessment & Severity Evaluation

Vulnerability Overview

EUVD-2026-2004 (CVE-2026-22783) is a critical-severity arbitrary file deletion vulnerability in DFIR-IRIS, a web-based collaborative platform for incident response (IR) and digital forensics (DFIR). The flaw arises from improper input validation and mass assignment in the datastore file management system, allowing authenticated users to delete arbitrary files on the underlying filesystem.

CVSS v3.1 Analysis

Metric	Value	Explanation
Attack Vector (AV)	Network (N)	Exploitable remotely via HTTP(S).
Attack Complexity (AC)	Low (L)	No specialized conditions required.
Privileges Required (PR)	Low (L)	Requires authenticated user access (standard IR team member).
User Interaction (UI)	None (N)	No victim interaction needed.
Scope (S)	Changed (C)	Impacts files outside the application’s intended security boundary.
Confidentiality (C)	None (N)	No data exposure, only deletion.
Integrity (I)	High (H)	Unauthorized file deletion can disrupt operations.
Availability (A)	High (H)	Critical system files can be deleted, causing DoS.
Base Score	9.6 (Critical)	High impact on integrity and availability with low attack complexity.

Severity Justification

• High Impact (I:H/A:H): Arbitrary file deletion can lead to system compromise, data loss, or denial of service (DoS).
• Low Attack Complexity (AC:L): Exploitation requires only authenticated access and three straightforward API calls (upload, update, delete).
• Changed Scope (S:C): The vulnerability bypasses filesystem isolation, allowing deletion of files outside the application’s intended directory.
• No Confidentiality Impact (C:N): While severe, the flaw does not expose sensitive data—only destructive actions are possible.

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2. Potential Attack Vectors & Exploitation Methods

Exploitation Chain

The vulnerability is exploited via a three-step attack chain:

1. File Upload (Initialization)

   • An authenticated user uploads a legitimate file to the DFIR-IRIS datastore.
   • The system assigns a file_local_name (stored path) and a file_id.

2. Mass Assignment Attack (Path Manipulation)

   • The attacker modifies the file_local_name field via an API request (e.g., PATCH /api/v1/datastore/file/{file_id}).
   • Due to improper input validation, the system trusts the updated path without sanitization.
   • The attacker sets file_local_name to an arbitrary filesystem path (e.g., /etc/passwd, C:\Windows\System32\config\SAM).

3. File Deletion (Exploitation)

   • The attacker triggers the delete operation (e.g., DELETE /api/v1/datastore/file/{file_id}).
   • The system blindly deletes the file at the manipulated path without validating its location.

Exploitation Requirements

• Authenticated Access: Attacker must have a valid DFIR-IRIS account (even low-privileged).
• API Access: Exploitation occurs via REST API calls (no direct UI interaction required).
• No Special Tools Needed: Can be executed using cURL, Burp Suite, or Postman.

Proof-of-Concept (PoC) Exploit

# Step 1: Upload a file (returns file_id)
curl -X POST -H "Authorization: Bearer <TOKEN>" \
     -F "file=@test.txt" \
     "https://iris.example.com/api/v1/datastore/file" | jq '.data.file_id'

# Step 2: Modify file_local_name to target /etc/passwd
curl -X PATCH -H "Authorization: Bearer <TOKEN>" \
     -H "Content-Type: application/json" \
     -d '{"file_local_name": "/etc/passwd"}' \
     "https://iris.example.com/api/v1/datastore/file/<file_id>"

# Step 3: Delete the file (deletes /etc/passwd)
curl -X DELETE -H "Authorization: Bearer <TOKEN>" \
     "https://iris.example.com/api/v1/datastore/file/<file_id>"

Post-Exploitation Impact

• System Compromise: Deletion of critical files (e.g., /etc/shadow, C:\Windows\System32\drivers\etc\hosts).
• Denial of Service (DoS): Removal of configuration files (e.g., /etc/nginx/nginx.conf, C:\Windows\System32\config\SYSTEM).
• Persistence Mechanisms: Attackers could delete log files to cover tracks.
• Lateral Movement: If DFIR-IRIS runs with high privileges, attackers could delete security tools (e.g., EDR/AV binaries).

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3. Affected Systems & Software Versions

Vulnerable Software

Product	Vendor	Affected Versions	Fixed Version
iris-web	dfir-iris	< 2.4.24	2.4.24+

Deployment Context

• Typical Installations:
  • On-premise deployments in SOCs, CERTs, and DFIR teams.
  • Cloud-based instances (if self-hosted).
• Privilege Context:
  • Runs under a service account (often with elevated filesystem permissions).
  • May be integrated with SIEMs, ticketing systems, or forensic tools.

Detection & Indicators of Compromise (IoCs)

• Log Entries:
  • Unusual PATCH requests modifying file_local_name.
  • DELETE operations targeting sensitive paths.
• Filesystem Artifacts:
  • Missing critical system files (e.g., /etc/passwd).
  • Unexpected deletions in /var/log/, /etc/, or C:\Windows\.
• Network Traffic:
  • API calls to /api/v1/datastore/file with suspicious payloads.

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4. Recommended Mitigation Strategies

Immediate Actions

1. Upgrade to Fixed Version

   • Patch immediately to DFIR-IRIS 2.4.24 or later.
   • Reference: GitHub Commit 57c1b80.

2. Temporary Workarounds (If Patching is Delayed)

   • Disable File Deletion API: Restrict DELETE /api/v1/datastore/file via WAF or reverse proxy rules.
   • Input Validation: Manually enforce strict path validation in the file_local_name field (e.g., allow only alphanumeric + ./-).
   • Least Privilege: Run DFIR-IRIS under a low-privilege service account with minimal filesystem access.
   • File Integrity Monitoring (FIM): Monitor critical system files for unauthorized changes.

3. Network-Level Protections

   • Web Application Firewall (WAF) Rules:
     • Block PATCH requests modifying file_local_name to absolute paths.
     • Rate-limit API calls to /api/v1/datastore/file.
   • Microsegmentation: Isolate DFIR-IRIS from critical internal systems.

Long-Term Security Improvements

• Code Review & Secure Development:
  • Implement strict input validation for all file operations.
  • Use whitelisting for allowed file paths (e.g., only within /var/iris/datastore/).
  • Enforce least privilege in API endpoints (e.g., restrict file deletion to admins).
• Automated Security Testing:
  • Integrate SAST/DAST tools (e.g., Semgrep, OWASP ZAP) into CI/CD pipelines.
  • Perform fuzz testing on file management APIs.
• Incident Response Preparedness:
  • Backup critical files before patching.
  • Monitor for exploitation attempts post-patch.

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5. Impact on the European Cybersecurity Landscape

Strategic & Operational Risks

• Critical Infrastructure Threat:
  • DFIR-IRIS is used by European CERTs, SOCs, and law enforcement (e.g., ENISA, national CSIRTs).
  • A successful attack could disrupt incident response operations during a major cyber incident.
• Supply Chain Risk:
  • If exploited, attackers could delete forensic evidence, hindering investigations.
  • May lead to false attribution in cybercrime cases.
• Regulatory & Compliance Implications:
  • GDPR (Art. 32): Failure to patch may result in non-compliance with security obligations.
  • NIS2 Directive: Critical entities must patch high-severity vulnerabilities within strict timelines.
  • ENISA Guidelines: Mandates vulnerability management for EU-based organizations.

Sector-Specific Concerns

Sector	Risk	Mitigation Priority
Government & Defense	Disruption of national cyber defense operations.	Critical (Patch within 24h)
Financial Services	Destruction of audit logs, compliance violations.	High (Patch within 72h)
Healthcare	Deletion of patient records, HIPAA violations.	High (Patch within 72h)
Energy & Utilities	Sabotage of SCADA/ICS forensic data.	Critical (Patch within 24h)

Geopolitical Considerations

• State-Sponsored Threats:
  • APT groups (e.g., APT29, Sandworm) could exploit this to erase forensic evidence after an attack.
• Cybercrime Exploitation:
  • Ransomware gangs may use this to delete backups before encryption.
• EU Cyber Resilience Act (CRA) Compliance:
  • Organizations must report critical vulnerabilities to ENISA within 24 hours of exploitation.

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6. Technical Details for Security Professionals

Root Cause Analysis

• Mass Assignment Vulnerability:
  • The API endpoint blindly accepts file_local_name updates without validating if the new path is within the intended directory.
  • No path canonicalization (e.g., resolving ../ sequences).
• Path Trust Issue:
  • The delete operation trusts the stored file_local_name without revalidating the path.
  • No filesystem boundary checks (e.g., ensuring the path is under /var/iris/datastore/).

Patch Analysis (GitHub Commit 57c1b80)

• Key Fixes:
  1. Input Validation:
     • Added regex-based validation for file_local_name (only allows [a-zA-Z0-9_\-\.]).
  2. Path Sanitization:
     • Strips leading/trailing slashes and resolves relative paths (../).
  3. Filesystem Boundary Enforcement:
     • Forces all file operations to stay within the datastore directory (/var/iris/datastore/).
  4. Privilege Escalation Prevention:
     • Restricts file deletion to admin roles (if not already enforced).

Forensic & Detection Guidance

• Log Analysis Queries (SIEM Rules):

  -- Splunk Example: Detect suspicious file_local_name updates
  index=iris sourcetype=iris_api
  | search method=PATCH uri="/api/v1/datastore/file/*"
  | regex _raw="\"file_local_name\":\"(/|C:\\\\|\\.\\./)"
  | table _time, user, file_id, file_local_name
  

• Filesystem Monitoring:
  • Use Auditd (Linux) or Sysmon (Windows) to log deletions of sensitive files.
  • Example Auditd rule:

    auditctl -w /etc/ -p w -k iris_arbitrary_deletion
    

Exploit Development Considerations

• Bypassing Mitigations:
  • If path validation is weak, attackers may use Unicode path traversal (e.g., %2e%2e%2f).
  • Race conditions could be exploited if file operations are not atomic.
• Post-Exploitation:
  • After deleting a file, attackers may replace it with a malicious version (e.g., SSH keys, cron jobs).

Reverse Engineering the Vulnerability

• Key API Endpoints:
  • POST /api/v1/datastore/file (Upload)
  • PATCH /api/v1/datastore/file/{file_id} (Update)
  • DELETE /api/v1/datastore/file/{file_id} (Delete)
• Database Schema (Relevant Fields):

  CREATE TABLE datastore_files (
      file_id INTEGER PRIMARY KEY,
      file_local_name TEXT,  -- Vulnerable field
      file_original_name TEXT,
      file_size INTEGER,
      file_hash TEXT,
      user_id INTEGER REFERENCES users(user_id)
  );
  

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Conclusion & Recommendations

Summary of Key Findings

• Critical-severity (CVSS 9.6) arbitrary file deletion vulnerability in DFIR-IRIS.
• Exploitable by authenticated users with minimal privileges.
• High risk to European CERTs, SOCs, and critical infrastructure due to DFIR-IRIS’s role in incident response.
• Patch available (v2.4.24+); temporary mitigations possible if immediate patching is infeasible.

Action Plan for Organizations

Priority	Action	Responsible Party
Immediate (0-24h)	Deploy patch (v2.4.24) or apply WAF rules.	IT/Security Teams
Short-Term (1-7 days)	Audit logs for exploitation attempts.	SOC/IR Teams
Medium-Term (1-4 weeks)	Review API security & implement least privilege.	DevSecOps
Long-Term (Ongoing)	Integrate SAST/DAST into CI/CD pipeline.	Development Teams

Final Risk Assessment

• Likelihood: High (Exploitation is straightforward; PoC available).
• Impact: Critical (System compromise, DoS, forensic evidence destruction).
• Risk Level: Extreme (Requires immediate remediation).

Organizations using DFIR-IRIS must treat this as a top-priority vulnerability and patch without delay. Failure to do so could result in catastrophic operational disruptions during a cyber incident.