CVE-2023-35890: IBM WebSphere Information Disclosure Flaw

CVE-2023-35890 Overview

IBM WebSphere Application Server versions 8.5 and 9.0 are affected by a cryptographic vulnerability that provides weaker than expected security due to improper encoding in a local configuration file. This weakness (CWE-327: Use of a Broken or Risky Cryptographic Algorithm) allows a local authenticated attacker with access to the configuration file to potentially extract sensitive information that should have been protected by proper encoding or encryption mechanisms.

Critical Impact

Local attackers with low-privilege access can read sensitive configuration data due to improper encoding, potentially leading to unauthorized information disclosure and further compromise of the application server environment.

Affected Products

• IBM WebSphere Application Server 8.5.5.23
• IBM WebSphere Application Server 9.0.5.15
• IBM WebSphere Application Server 9.0.5.16

Discovery Timeline

• 2023-07-07 - CVE-2023-35890 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-35890

Vulnerability Analysis

This vulnerability stems from the use of improper encoding mechanisms in IBM WebSphere Application Server's local configuration files. Configuration files in enterprise application servers often contain sensitive information such as database credentials, API keys, and other secrets that should be protected through strong encryption or encoding.

The improper encoding implementation in affected versions of WebSphere Application Server means that sensitive data stored within configuration files may not be adequately protected. An attacker with local access and low-level privileges could potentially decode or read this information, leading to high-impact confidentiality breaches while not directly affecting integrity or availability.

The vulnerability requires local access to the system, meaning remote exploitation is not possible. However, in multi-tenant environments or systems with multiple local users, this presents a significant security concern as any authenticated local user could potentially access sensitive configuration data.

Root Cause

The root cause of CVE-2023-35890 is the use of a broken or risky cryptographic algorithm (CWE-327) for encoding sensitive data in local configuration files. IBM WebSphere Application Server implemented weaker than expected encoding mechanisms, failing to adequately protect configuration file contents from local access by authenticated users.

This type of vulnerability often occurs when legacy encoding methods are used instead of modern cryptographic standards, or when developers implement custom encoding schemes that do not provide adequate security. The configuration file handling code fails to apply appropriate cryptographic protections to sensitive values.

Attack Vector

The attack vector for this vulnerability is local access with low privilege requirements. An attacker would need authenticated access to the system where IBM WebSphere Application Server is installed. The exploitation process involves:

1. The attacker gains local access to the system running WebSphere Application Server
2. The attacker locates the vulnerable configuration files within the WebSphere installation directory
3. Due to improper encoding, the attacker can read or decode sensitive information from these configuration files
4. The exposed information may include credentials, connection strings, or other sensitive data that could enable further attacks

Since no proof-of-concept exploits have been publicly released and the vulnerability is not listed in CISA's Known Exploited Vulnerabilities catalog, exploitation in the wild has not been confirmed. However, organizations should treat this as a priority remediation item due to the potential for sensitive data exposure.

Detection Methods for CVE-2023-35890

Indicators of Compromise

• Unexpected file access attempts on WebSphere configuration directories by non-administrative users
• Anomalous read operations on configuration files such as security.xml, server.xml, or files within the config directory
• Local user accounts accessing WebSphere installation directories without legitimate business justification
• Evidence of configuration file contents being copied or exfiltrated from the system

Detection Strategies

• Implement file integrity monitoring (FIM) on WebSphere Application Server configuration directories to detect unauthorized access or modifications
• Configure audit logging for file system access to WebSphere configuration files, monitoring for non-administrative users accessing sensitive paths
• Deploy endpoint detection solutions to monitor for suspicious local file access patterns within WebSphere installation directories
• Use SentinelOne's behavioral AI to detect anomalous access patterns to application server configuration files

Monitoring Recommendations

• Enable detailed file access auditing on the WebSphere Application Server installation directory, particularly /opt/IBM/WebSphere/AppServer/profiles/*/config/
• Configure SIEM alerts for multiple configuration file access attempts from the same user account within a short time window
• Monitor for processes attempting to decode or parse WebSphere configuration files outside of normal server operations
• Establish baseline access patterns for configuration files and alert on deviations

How to Mitigate CVE-2023-35890

Immediate Actions Required

• Apply the security patches provided by IBM for WebSphere Application Server 8.5 and 9.0 immediately
• Review and restrict file system permissions on WebSphere configuration directories to limit access to only required administrative accounts
• Audit current user access to systems running vulnerable WebSphere Application Server instances
• Rotate any credentials or sensitive values stored in WebSphere configuration files after patching

Patch Information

IBM has released security updates to address this vulnerability. Organizations should refer to the IBM Support Page (Node 7007857) for detailed patch information and download links. The advisory, tracked as IBM X-Force ID: 258637, provides specific fix pack versions and installation instructions.

For WebSphere Application Server 8.5, upgrade to a version newer than 8.5.5.23 that includes the security fix. For WebSphere Application Server 9.0, upgrade to a version newer than 9.0.5.16 that addresses the improper encoding issue.

Workarounds

• Restrict local access to systems running WebSphere Application Server to only essential personnel
• Implement strict file system permissions on configuration directories, ensuring only the WebSphere service account and administrators have read access
• Consider using external credential stores or vault solutions for sensitive configuration values rather than storing them directly in configuration files
• Deploy additional access controls such as SELinux or AppArmor policies to restrict access to WebSphere configuration files

# Configuration example - Restrict configuration file permissions
# Navigate to WebSphere configuration directory
cd /opt/IBM/WebSphere/AppServer/profiles/*/config/

# Set restrictive permissions on configuration files
chmod 600 *.xml
chown wasadmin:wasgroup *.xml

# Verify the permissions
ls -la *.xml