CVE-2024-39338: Axios SSRF Vulnerability

CVE-2024-39338 Overview

CVE-2024-39338 is a Server-Side Request Forgery (SSRF) vulnerability affecting Axios 1.7.2, a widely-used promise-based HTTP client for Node.js and browsers. The vulnerability stems from unexpected behavior where requests for path relative URLs are incorrectly processed as protocol relative URLs, potentially allowing attackers to redirect requests to arbitrary destinations.

Critical Impact

This SSRF vulnerability can enable attackers to access internal services, exfiltrate sensitive data, or pivot to other systems within a network by manipulating URL handling in applications using vulnerable Axios versions.

Affected Products

• Axios versions prior to patched release (specifically 1.7.2)
• Node.js applications using vulnerable Axios versions
• Web applications with server-side Axios implementations

Discovery Timeline

• 2024-08-12 - CVE-2024-39338 published to NVD
• 2024-08-23 - Last updated in NVD database

Technical Details for CVE-2024-39338

Vulnerability Analysis

This vulnerability is classified as CWE-918 (Server-Side Request Forgery). The root issue lies in how Axios 1.7.2 handles path relative URLs during request processing. When an application passes a path relative URL (e.g., /api/endpoint) to Axios, the library incorrectly interprets certain URL patterns as protocol relative URLs (e.g., //attacker.com), causing requests to be sent to unintended destinations.

SSRF vulnerabilities are particularly dangerous in server-side applications because they can bypass network security controls. An attacker who can influence the URL parameter passed to Axios may be able to make the vulnerable server issue requests to internal services, cloud metadata endpoints, or other sensitive resources that would normally be inaccessible from external networks.

Root Cause

The vulnerability originates from improper URL parsing logic within Axios that fails to correctly distinguish between path relative URLs and protocol relative URLs. When processing URLs, the library's parsing mechanism mishandles edge cases where path components resemble protocol relative patterns, leading to unintended request routing.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by providing specially crafted URL inputs to an application using Axios. If the application passes user-controlled data to Axios request methods without proper validation, the attacker can redirect server-side requests to arbitrary destinations.

For example, an attacker might supply a malicious path that Axios incorrectly processes as a protocol relative URL, causing the server to issue requests to attacker-controlled infrastructure or internal network resources. This can lead to:

• Access to internal services and APIs not exposed to the internet
• Retrieval of cloud instance metadata (e.g., AWS metadata service at 169.254.169.254)
• Port scanning of internal networks
• Exfiltration of sensitive data from internal resources

Technical details and proof-of-concept information are available in the Jeff Hacks CVE-2024-39338 Advisory.

Detection Methods for CVE-2024-39338

Indicators of Compromise

• Unexpected outbound HTTP/HTTPS requests from servers running Node.js applications
• Requests to internal IP ranges (e.g., 10.x.x.x, 172.16.x.x, 192.168.x.x) or localhost from application servers
• Attempts to access cloud metadata endpoints (e.g., 169.254.169.254)
• Anomalous DNS lookups for internal hostnames originating from application servers

Detection Strategies

• Implement network monitoring to detect unusual outbound traffic patterns from application servers
• Deploy web application firewalls (WAF) with rules to detect SSRF patterns in request parameters
• Review application logs for requests containing suspicious URL patterns or unexpected redirects
• Utilize SentinelOne Singularity to monitor for anomalous network behavior from Node.js processes

Monitoring Recommendations

• Enable detailed logging for all outbound HTTP requests made by application servers
• Configure alerts for connections to private IP ranges or cloud metadata endpoints
• Monitor DNS resolution logs for queries that could indicate SSRF exploitation attempts
• Implement egress filtering and monitor for violations

How to Mitigate CVE-2024-39338

Immediate Actions Required

• Audit all applications using Axios to identify vulnerable versions (1.7.2 and potentially earlier)
• Update Axios to the latest patched version immediately
• Implement URL validation and sanitization for all user-controlled inputs passed to HTTP clients
• Deploy network-level controls to restrict outbound requests from application servers

Patch Information

The Axios maintainers have addressed this vulnerability in subsequent releases. Organizations should upgrade to the latest stable version of Axios available from the GitHub Axios Releases page. Review the release notes to confirm the specific version that includes the fix for CVE-2024-39338.

Workarounds

• Implement strict URL validation before passing any user input to Axios request methods
• Use allowlists to restrict which domains/hosts the application can make requests to
• Deploy network egress controls to prevent application servers from accessing internal resources or metadata endpoints
• Consider using a URL parsing library to validate and normalize URLs before passing them to Axios

# Example: Verify Axios version in your Node.js project
npm list axios

# Update Axios to latest version
npm update axios

# Or install specific patched version
npm install axios@latest