CVE-2025-27907: IBM WebSphere Application Server SSRF Flaw

CVE-2025-27907 Overview

IBM WebSphere Application Server versions 8.5 and 9.0 contain a Server-Side Request Forgery (SSRF) vulnerability that allows authenticated attackers to send unauthorized requests from the server. This security flaw could enable malicious actors to perform network enumeration of internal resources or leverage the compromised server as a pivot point for launching additional attacks against internal infrastructure.

Critical Impact

Authenticated attackers can exploit this SSRF vulnerability to make the WebSphere Application Server send arbitrary requests to internal or external systems, potentially exposing sensitive internal network topology and facilitating lateral movement within corporate environments.

Affected Products

• IBM WebSphere Application Server 8.5
• IBM WebSphere Application Server 9.0
• Deployments on HP-UX, IBM AIX, IBM i, IBM z/OS, Linux, Microsoft Windows, and Oracle Solaris

Discovery Timeline

• April 22, 2025 - CVE-2025-27907 published to NVD
• July 18, 2025 - Last updated in NVD database

Technical Details for CVE-2025-27907

Vulnerability Analysis

This SSRF vulnerability (CWE-918) in IBM WebSphere Application Server allows authenticated users with high privileges to manipulate server-side HTTP requests. The vulnerability requires network access and does not require user interaction to exploit. While the attack complexity is low, the requirement for high privileges limits the immediate attack surface. Successful exploitation results in limited confidentiality impact through unauthorized information disclosure, with no direct impact on system integrity or availability.

Root Cause

The root cause of CVE-2025-27907 lies in insufficient validation of user-supplied URLs or request parameters within the WebSphere Application Server. When the application server processes certain requests, it fails to properly sanitize or restrict the destination of outbound HTTP requests, allowing an authenticated attacker to specify arbitrary internal or external endpoints as request targets.

Attack Vector

The attack vector for this vulnerability is network-based, requiring the attacker to have authenticated access to the WebSphere Application Server with elevated privileges. An attacker could craft malicious requests that cause the server to:

• Probe internal network resources that would otherwise be inaccessible from external networks
• Enumerate internal services and their versions by analyzing response behavior
• Access metadata services in cloud environments (such as AWS EC2 metadata endpoints)
• Bypass network segmentation controls by using the WebSphere server as a proxy

The vulnerability can be exploited by manipulating request parameters to include internal IP addresses, localhost references, or cloud metadata URLs. The server then processes these requests with its own network context and privileges, potentially returning sensitive information to the attacker.

Detection Methods for CVE-2025-27907

Indicators of Compromise

• Unusual outbound HTTP/HTTPS requests from WebSphere Application Server to internal IP ranges (e.g., 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
• Requests targeting cloud metadata endpoints such as 169.254.169.254
• Anomalous access patterns from privileged administrative accounts
• Server-originated requests to previously unknown internal hosts or services

Detection Strategies

• Monitor WebSphere Application Server logs for requests containing internal IP addresses or localhost references in URL parameters
• Implement network-level monitoring to detect unusual outbound connections from application server hosts
• Deploy web application firewall (WAF) rules to identify SSRF patterns in incoming requests
• Analyze authentication logs for suspicious privileged account activity correlating with network anomalies

Monitoring Recommendations

• Enable verbose logging on WebSphere Application Server to capture full request details including URLs and parameters
• Configure network intrusion detection systems (IDS) to alert on application server connections to internal RFC 1918 addresses
• Establish baseline network behavior for WebSphere servers and alert on deviations
• Monitor for failed connection attempts to internal services that may indicate reconnaissance activity

How to Mitigate CVE-2025-27907

Immediate Actions Required

• Review and restrict administrative access to WebSphere Application Server, applying principle of least privilege
• Implement network segmentation to limit outbound connectivity from application servers
• Apply IBM's security patch as outlined in the vendor advisory
• Audit privileged account usage and remove unnecessary high-privilege access

Patch Information

IBM has released a security update to address this vulnerability. Administrators should apply the official patch available through IBM Support Page. Organizations running WebSphere Application Server versions 8.5 and 9.0 should prioritize patching based on their environment's exposure and the sensitivity of internal network resources accessible from the application server.

Workarounds

• Implement egress filtering on network firewalls to restrict outbound connections from WebSphere Application Server hosts
• Configure application-level URL allowlists where possible to prevent requests to arbitrary destinations
• Deploy a web application firewall with SSRF-specific detection rules in front of WebSphere deployments
• Isolate WebSphere Application Servers in network segments with strict outbound traffic controls

# Example network-level mitigation using iptables to restrict outbound connections
# Block outbound connections to internal networks from WebSphere server
iptables -A OUTPUT -p tcp -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -p tcp -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -p tcp -d 192.168.0.0/16 -j DROP
iptables -A OUTPUT -p tcp -d 169.254.169.254 -j DROP

# Allow only necessary outbound connections (customize as needed)
# Note: Apply these rules on the WebSphere Application Server host