Description

Insufficient input validation in ABR allows a low-privileged user to inject malicious entries into the sudoers file, resulting in persistent root access that remained effective after the ABR session ended.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-26T08:16:46.720Z",
  "pubdate": "2026-08-26T08:16:46.720Z",
  "executiveSummary": "This vulnerability involves insufficient input validation within the ABR system, allowing low-privileged users to achieve unauthorized privilege escalation to root.\nThe flaw stems from a lack of sanitization during the processing of configuration or policy updates, which enables the injection of malicious entries into the system's 'sudoers' file.\nSuccessful exploitation results in full root-level persistence, which remains active even after the initial ABR session is terminated.\nThe risk implication is critical, as it bypasses standard access control mechanisms and provides an attacker with complete system control.\nAn attacker requires low-privileged user access to the ABR environment to perform the injection, but no further complex prerequisites are mentioned.\nThe vulnerability highlights a failure in integrity checking for sensitive configuration files, ultimately leading to a complete compromise of the host security posture.",
  "technicalDetails": "The core root cause of this vulnerability is improper sanitization and validation of user-supplied data during interactions with the ABR subsystem.\nThe system fails to adequately verify input strings before processing them against critical system configuration files, specifically the 'sudoers' file located on the filesystem.\nAn attacker can exploit this by crafting a malicious payload containing sudoers configuration syntax. When processed by the ABR component, this payload is appended or written to the 'sudoers' file due to the lack of input filtering or boundary checks.\nThe exploitation flow begins with the attacker establishing a low-privileged session within the ABR environment. Once the session is active, the attacker triggers the vulnerable function responsible for updating configuration or logging entries, supplying the malicious payload as an input argument.\nThe ABR process, executing with elevated permissions, inadvertently treats the malicious input as trusted data and writes it into the 'sudoers' file. This creates a new entry granting the attacker's user account (or a controlled service account) NOPASSWD access to root privileges.\nBecause the 'sudoers' file is a system-wide policy enforcement mechanism, the changes are immediately committed and persist beyond the lifecycle of the specific ABR session. The malicious entry remains in the file until explicitly removed by a system administrator.\nPost-exploitation impact is catastrophic, granting the attacker unrestricted root-level access to the underlying operating system. This allows for arbitrary command execution, data exfiltration, installation of backdoors, and complete subversion of security auditing mechanisms.\nThe vulnerability is restricted to environments where the ABR component manages or influences system-level configuration files without secondary validation layers. The persistence mechanism is inherent to the nature of the 'sudoers' file, which dictates authorization policies for the system’s execution environment."
}