CVE-2022-47986: IBM Aspera Faspex RCE Vulnerability

CVE-2022-47986 Overview

CVE-2022-47986 is a critical insecure deserialization vulnerability affecting IBM Aspera Faspex 4.4.2 Patch Level 1 and earlier versions. The flaw exists in the handling of YAML deserialization through an obsolete API call, allowing remote attackers to execute arbitrary code on vulnerable systems without authentication. By sending specially crafted requests to the deprecated API endpoint, attackers can exploit this YAML deserialization flaw to achieve complete system compromise.

Critical Impact

This vulnerability enables unauthenticated remote code execution through YAML deserialization, allowing attackers to gain full control of affected IBM Aspera Faspex servers. This CVE is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild.

Affected Products

• IBM Aspera Faspex versions prior to 4.4.2
• IBM Aspera Faspex 4.4.2 (without patch level)
• IBM Aspera Faspex 4.4.2 Patch Level 1

Discovery Timeline

• 2023-02-17 - CVE-2022-47986 published to NVD
• 2025-10-27 - Last updated in NVD database

Technical Details for CVE-2022-47986

Vulnerability Analysis

This vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). IBM Aspera Faspex is a web-based file exchange application designed for enterprise environments to transfer large files and data sets. The application contains an obsolete API endpoint that improperly handles YAML input, leading to unsafe deserialization of user-controlled data.

The flaw allows remote attackers to craft malicious YAML payloads that, when processed by the vulnerable API, result in arbitrary code execution on the underlying system. Since the vulnerable API call does not require authentication, any network-accessible Faspex instance running an affected version is at risk of exploitation. The vulnerability affects deployments on both Linux and Windows operating systems.

Root Cause

The root cause of CVE-2022-47986 lies in the improper handling of YAML deserialization within an obsolete API endpoint. The application fails to properly validate or sanitize YAML input before deserializing it, allowing attackers to inject malicious objects into the deserialization process. YAML parsers in Ruby (which Aspera Faspex uses) can instantiate arbitrary Ruby objects when processing specially crafted YAML documents, leading to remote code execution when dangerous classes are deserialized.

Attack Vector

The attack is conducted over the network without requiring any authentication or user interaction. An attacker can send a specially crafted HTTP request containing a malicious YAML payload to the obsolete API endpoint. When the Faspex server processes this request, the YAML parser deserializes the malicious payload, triggering arbitrary code execution with the privileges of the Faspex application.

The obsolete API endpoint that was vulnerable has been removed in Faspex 4.4.2 PL2. Organizations running earlier versions should assume the attack surface is exposed to any network entity that can reach the Faspex web interface.

Detailed technical analysis and proof-of-concept information can be found in the Packet Storm Exploit Analysis.

Detection Methods for CVE-2022-47986

Indicators of Compromise

• Unusual HTTP POST requests to legacy or obsolete Faspex API endpoints
• Web server logs containing YAML-formatted payloads with Ruby object instantiation syntax (e.g., !ruby/object: or !ruby/hash:)
• Unexpected child processes spawned by the Faspex web application
• Anomalous outbound network connections originating from the Faspex server

Detection Strategies

• Monitor web application logs for requests to deprecated API endpoints and unusual YAML content in request bodies
• Implement network intrusion detection rules to identify YAML deserialization attack patterns targeting Faspex
• Deploy endpoint detection and response (EDR) solutions to detect suspicious process execution chains originating from web application processes
• Review web application firewall (WAF) logs for blocked requests containing serialized Ruby objects

Monitoring Recommendations

• Enable verbose logging on IBM Aspera Faspex instances to capture detailed request information
• Configure SIEM alerts for any requests containing Ruby object serialization indicators
• Monitor system integrity on Faspex servers for unauthorized file modifications or new processes
• Implement network segmentation to limit exposure of Faspex servers to trusted networks only

How to Mitigate CVE-2022-47986

Immediate Actions Required

• Upgrade IBM Aspera Faspex to version 4.4.2 Patch Level 2 or later immediately
• If immediate patching is not possible, restrict network access to the Faspex web interface to trusted IP addresses only
• Conduct forensic analysis on potentially exposed systems to identify signs of compromise
• Review system and application logs for evidence of exploitation attempts

Patch Information

IBM has addressed this vulnerability by removing the obsolete API call in Faspex 4.4.2 PL2. Organizations should apply this patch as soon as possible given the critical severity and known active exploitation. The official security bulletin and patch information is available in the IBM Support Document. Additional vulnerability details can be found in the IBM X-Force Vulnerability ID 243512.

Given that this vulnerability is listed in the CISA Known Exploited Vulnerabilities Catalog, federal agencies and organizations following CISA guidance are required to remediate this vulnerability according to specified timelines.

Workarounds

• Implement network-level access controls to restrict access to the Faspex web interface from untrusted networks
• Deploy a web application firewall (WAF) with rules to block requests containing YAML deserialization attack patterns
• Consider taking vulnerable Faspex instances offline until patching can be completed
• Monitor for and block requests containing Ruby object serialization syntax in request bodies

# Example: Restrict Faspex access using iptables (Linux)
# Allow access only from trusted management network
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP