Description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a local attacker to execute arbitrary commands due to improper neutralization of special elements used in an OS command.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.4",
  "pubDate": "2026-09-04T17:16:54.937Z",
  "pubdate": "2026-09-04T17:16:54.937Z",
  "executiveSummary": "A command injection vulnerability exists in IBM i versions 7.3, 7.4, 7.5, and 7.6. The flaw arises from improper neutralization of special elements used in an OS command, which may allow a local attacker to execute arbitrary system commands with elevated privileges.\nThis vulnerability is classified as an OS Command Injection issue. It poses a significant security risk, as a local authenticated user could potentially gain unauthorized control over the operating system, access sensitive data, or disrupt system availability.\nThe primary requirement for exploitation is local access to the target system. The vulnerability is triggered by supplying malformed input to a vulnerable interface or system function that fails to properly sanitize or validate user-supplied input before passing it to an underlying shell or command execution environment.\nSuccessful exploitation allows an attacker to bypass standard security controls, potentially leading to privilege escalation or complete system compromise. IBM i administrators should prioritize applying available security patches or configuration hardening recommended by IBM to mitigate this threat.",
  "technicalDetails": "The vulnerability originates from a failure to correctly sanitize input arguments when passing user-supplied data to system-level commands or shell interfaces within the IBM i environment. In IBM i versions 7.3, 7.4, 7.5, and 7.6, specific components fail to neutralize special shell metacharacters (e.g., semicolons, pipe characters, or redirection operators) effectively.\nThis behavior facilitates command injection, wherein an attacker injects arbitrary OS commands into a legitimate input field. When the vulnerable component processes this tainted input, the operating system interprets the injected characters as control sequences, executing the attacker's payload alongside or instead of the intended command.\nThe exploitation flow typically begins with an authenticated local user identifying an interface or system utility that performs inadequate input validation. The attacker crafts a payload designed to terminate the intended command and initiate a secondary malicious process. For example, by inserting command separators, an attacker forces the system to interpret the trailing payload as a distinct instruction with the context of the calling process.\nBecause the vulnerable components often execute with high-level system permissions (such as those associated with the QSYS library or specific administrative service profiles), the injected commands are executed with elevated privileges. This circumvents the intended security boundaries of the IBM i profile-based access control system.\nPost-exploitation impact includes, but is not limited to, unauthorized access to user-protected libraries, modification of configuration files, execution of unauthorized system functions, or the persistent installation of backdoors. The vulnerability is restricted to local attackers, requiring valid credentials or an existing session on the machine. No remote network exposure is typically required, though this depends on whether the vulnerable component is accessible via remote services like Telnet, SSH, or specific middleware APIs that interface with the underlying OS command execution layer.\nThe root cause is a fundamental flaw in the input parsing logic of the affected system services, which lack sufficient abstraction or utilize insecure system calls (such as those susceptible to shell expansion) without adequate sanitization protocols."
}