Description

A flaw was found in Foreman. The foreman-tail utility is vulnerable to OS command injection due to the unsafe use of the eval command. The script takes user-supplied arguments and incorporates them directly into a string that is then executed by eval to expand file paths. Because the input is not sanitized or quoted, a local attacker can inject shell metacharacters (e.g., ;, &, |) to execute arbitrary system commands.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.3",
  "pubDate": "2026-10-01T18:17:15.033Z",
  "pubdate": "2026-10-01T18:17:15.033Z",
  "executiveSummary": "The foreman-tail utility in Foreman is susceptible to an OS command injection vulnerability originating from unsafe input handling.\nThe flaw resides in the improper utilization of the eval command, which parses user-supplied arguments to resolve file paths without adequate sanitization or input validation.\nThis vulnerability enables a local attacker to manipulate input strings by injecting shell metacharacters such as semicolons, ampersands, or pipe operators, effectively breaking out of the intended execution context.\nSuccessful exploitation allows an unprivileged local user to execute arbitrary system commands with the privileges of the user running foreman-tail.\nThe risk implication is significant as it provides a mechanism for local privilege escalation or unauthorized command execution on the host system.\nNo specific network-level exploitation is required; the primary vector is local access to the utility, making it a critical concern for multi-user environments or systems where untrusted local users have execution rights.",
  "technicalDetails": "The vulnerability is rooted in the implementation of the foreman-tail script, which performs path expansion using the eval shell command. The script incorrectly treats user-provided command-line arguments as trusted data, directly concatenating these inputs into an executable string. In shell programming, the eval command executes its arguments as a shell command; when this function processes unsanitized input, it treats any shell metacharacters contained within that input as control instructions rather than literal strings.\nThe attack flow begins when an attacker invokes foreman-tail with a crafted argument string. For instance, an attacker could supply a path argument containing shell metacharacters (e.g., 'file.log; id;'). Because the script passes this directly to eval, the shell interprets the semicolon as a command separator. Consequently, the shell first attempts to process the file path and subsequently executes the arbitrary command (in this case, 'id') injected by the attacker.\nThe vulnerable component is identified as the foreman-tail utility. Since the evaluation occurs at the shell level, any command injected by the attacker will execute with the identity and permissions of the user process invoking the utility. This creates a severe security boundary violation, as the utility is intended for file monitoring but becomes a proxy for arbitrary code execution.\nExploitation does not require elevated privileges initially, provided the user has execute access to the foreman-tail binary. The payload behavior is limited only by the permissions of the user executing the command. If the utility is invoked by a root-level process or a service account with high privileges, the injected commands will inherit those same security contexts, potentially leading to full system compromise.\nThe lack of proper input sanitization, such as argument quoting or the use of safer alternative functions for path expansion (like globbing mechanisms that do not invoke a shell), represents a fundamental flaw in the input processing logic of the script. The absence of strict input validation allows for the escape of the intended file-path argument, permitting the injection of arbitrary shell commands that the operating system interprets as part of the intended instruction set."
}