CVE-2026-78624 in Access Gateway
Summary
by MITRE • 09/08/2026
The Okta Access Gateway backup restore function does not validate the filename embedded in an encrypted backup payload. This results in writing file contents to unintended locations on the appliance filesystem.
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Analysis
by VulDB Data Team • 09/08/2026
Okta Access Gateway contains a critical path traversal vulnerability within its backup and restore functionality that allows for unauthorized file system writes, potentially leading to remote code execution or complete compromise of the underlying operating system. The core technical flaw stems from insufficient validation of filenames embedded within encrypted backup payloads during the restoration process. When an administrator initiates a restore operation, the application extracts files from the archive but fails to sanitize the internal path names before writing them to disk. This lack of input validation permits attackers to manipulate file paths using standard directory traversal sequences such as dot-dot-slash characters. By crafting a malicious backup payload with carefully constructed filenames containing these sequences, an attacker can direct the restore function to write files outside the designated application directories and into arbitrary locations on the appliance filesystem.
The operational impact of this vulnerability is severe because it bypasses normal access controls associated with specific application folders. An adversary who gains access to the management interface or intercepts backup traffic can exploit this flaw to overwrite critical system binaries, configuration files, or web server scripts. For instance, writing a malicious script into a directory served by an embedded web server could allow for remote code execution without requiring additional authentication vectors beyond those needed to initiate the restore process. This capability effectively neutralizes the security boundary of the appliance, as it grants the attacker write access to sensitive areas of the file system that are typically protected from user-level modifications. The encryption of the backup payload does not mitigate this risk because the vulnerability lies in the post-decryption handling of metadata rather than the decryption process itself.
From a classification perspective, this issue aligns with CWE-22 Improper Limitation of a Pathname to a Restricted Directory and CWE-73 External Control of File Name or Path. These categories highlight the failure to enforce strict boundaries on file system operations based on user-supplied input. In terms of offensive security frameworks, this vulnerability facilitates techniques associated with ATT&CK T1059 Command and Scripting Interpreter if an attacker writes executable scripts, or T1222 File and Directory Permissions Modification if they alter permissions to escalate privileges further. The exploitation chain typically involves creating a malicious archive, uploading it through the restore interface, and triggering the write operation that places payloads in strategic locations for subsequent execution.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Okta has released patches addressing this specific flaw by implementing strict path canonicalization and validation checks before any file system operations are performed. Administrators should apply these updates immediately to close the exposure window. Additionally, organizations running unpatched instances should restrict network access to the management interface of Okta Access Gateway appliances using firewalls or virtual private networks to prevent unauthorized users from initiating restore operations. Input sanitization remains a critical defense-in-depth measure; developers must ensure that all file names extracted from archives are validated against an allowlist of acceptable characters and paths, ensuring they remain within the expected application directory structure regardless of encryption status. Regular auditing of backup procedures and monitoring for unusual file system changes can also help detect exploitation attempts in real time.