Description

IBM WebSphere Application Server 9.0, and 8.5 could allow a remote attacker to inject forged log entries into the server's administrative log.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.8",
  "pubDate": "2026-09-14T20:16:40.020Z",
  "pubdate": "2026-09-14T20:16:40.020Z",
  "executiveSummary": "A log injection vulnerability exists in IBM WebSphere Application Server 9.0 and 8.5, which permits remote attackers to insert arbitrary, forged entries into administrative log files.\nThe vulnerability involves the improper sanitization of user-supplied input before it is processed and written to the server's logging infrastructure.\nSuccessful exploitation allows an attacker to manipulate the integrity of system logs, potentially misleading administrators or forensic investigators during incident response and security auditing.\nThis vulnerability affects versions 9.0 and 8.5 of the product. The exploit is performable by remote, unauthenticated, or low-privileged actors depending on the specific endpoint access control.\nThe primary risk implication is the degradation of trust in log-based security monitoring, potentially enabling an attacker to mask malicious activities, trigger false alerts, or perform log-based injection attacks that deceive downstream security information and event management (SIEM) systems.",
  "technicalDetails": "The vulnerability resides within the logging mechanism of IBM WebSphere Application Server, specifically in how the administrative interface handles parameters that are subsequently appended to server-side logs.\nThe root cause is an improper neutralization of log forging characters within input fields that lack sufficient validation before being passed to the logging subsystem. When an attacker supplies a string containing CRLF (Carriage Return and Line Feed) sequences or other control characters, the server fails to escape these inputs, allowing the termination of the current log entry and the insertion of a new, forged entry.\nThe attack flow begins with the attacker identifying an endpoint that accepts input and reflects it into the administrative logs. By crafting a request payload that includes encoded newline characters (e.g., %0d%0a), the attacker can terminate the legitimate log entry structure.\nFollowing the newline, the attacker appends a synthetic log record that mimics the format of legitimate administrative actions. Because the logging subsystem processes the input as trusted data, it appends the attacker-defined message to the log file as a new line.\nThis manipulation can cause several post-exploitation impacts. First, an attacker can create a false trail of administrative activity to frame legitimate users or mask their own unauthorized access attempts. Second, if the log files are parsed by automated security tools, the injected entries can trigger false positives, leading to exhaustion of SOC resources or the triggering of automated blocking mechanisms that could disrupt service for legitimate users.\nThe exploitation does not necessarily require the attacker to compromise the underlying operating system directly; rather, it exploits the logic of the application's logging process. In many deployments, administrative interfaces are exposed via network-accessible ports, increasing the risk of remote exploitation if proper access control lists (ACLs) or perimeter defenses are not configured to restrict access to management functions."
}