CVE-2025-15339: Tanium Discover Auth Bypass Vulnerability

CVE-2025-15339 Overview

Tanium has addressed an incorrect default permissions vulnerability in their Discover product. This security flaw (CWE-276) stems from improper default permission configurations that could allow privileged attackers to gain unauthorized access to sensitive data or modify system configurations. The vulnerability requires network access and high privileges to exploit, but once exploited, it can lead to significant confidentiality and integrity impacts.

Critical Impact

Attackers with high privileges could exploit incorrect default permissions in Tanium Discover to access or modify sensitive information, potentially compromising enterprise endpoint visibility and management capabilities.

Affected Products

• Tanium Discover (specific affected versions not disclosed)

Discovery Timeline

• 2026-02-05 - CVE CVE-2025-15339 published to NVD
• 2026-02-05 - Last updated in NVD database

Technical Details for CVE-2025-15339

Vulnerability Analysis

This vulnerability falls under CWE-276 (Incorrect Default Permissions), which occurs when software sets default permissions that allow unintended actors to access or modify resources. In the context of Tanium Discover—an endpoint discovery and asset management solution—this flaw could enable privileged users to access resources beyond their intended authorization scope.

The vulnerability affects the confidentiality and integrity of the system without impacting availability. An attacker exploiting this flaw would need to already possess high-level privileges within the environment, which somewhat limits the attack surface but does not diminish the potential impact of successful exploitation.

Root Cause

The root cause of this vulnerability is incorrect default permissions configured within Tanium Discover. When software components or resources are deployed with overly permissive default access controls, it creates opportunities for privilege abuse. In enterprise environments where Tanium Discover is used for endpoint visibility, such misconfigurations could expose sensitive asset discovery data or allow unauthorized modifications to discovery configurations.

Attack Vector

The attack vector is network-based, requiring no user interaction. An authenticated attacker with high privileges would need to:

1. Gain authenticated access to the Tanium environment with elevated privileges
2. Identify resources with incorrect default permissions
3. Leverage the misconfigured permissions to access sensitive information or modify configurations

Due to the nature of the incorrect permissions vulnerability, exploitation would involve accessing resources that should have been restricted, even for privileged users. The attack does not change the scope of the vulnerability, meaning the impact remains within the vulnerable component's security context.

Detection Methods for CVE-2025-15339

Indicators of Compromise

• Unusual access patterns to Tanium Discover configuration files or sensitive data stores
• Unauthorized modifications to discovery policies or asset groupings
• Anomalous privileged user activity accessing resources outside normal operational patterns
• Audit log entries showing access to restricted resources by users with elevated privileges

Detection Strategies

• Review Tanium Discover audit logs for access to sensitive resources by users who should not have permissions
• Monitor for configuration changes to discovery settings or permission assignments
• Implement behavioral analysis to detect privileged users accessing resources outside their normal scope
• Deploy file integrity monitoring on critical Tanium Discover configuration files

Monitoring Recommendations

• Enable comprehensive audit logging within Tanium Discover and forward logs to a SIEM solution
• Configure alerts for permission-related configuration changes
• Regularly review access control lists and compare against baseline configurations
• Monitor network traffic for unusual patterns between Tanium components

How to Mitigate CVE-2025-15339

Immediate Actions Required

• Review the Tanium Security Advisory TAN-2025-029 for specific remediation guidance
• Audit current Tanium Discover permissions and apply principle of least privilege
• Review user access levels and remove unnecessary elevated privileges
• Implement additional access controls where possible until patches are applied

Patch Information

Tanium has addressed this vulnerability as documented in their security advisory. Organizations should consult the Tanium Security Advisory TAN-2025-029 for specific patch information, affected versions, and upgrade instructions. Contact Tanium support for guidance on obtaining and applying the security update.

Workarounds

• Review and restrict default permissions on Tanium Discover resources pending patch application
• Limit network access to Tanium Discover to trusted management networks only
• Implement additional monitoring and logging to detect potential exploitation attempts
• Review and audit all users with high-privilege access to reduce the potential attack surface