A critical path traversal vulnerability (CVE-2025-26692) affecting SIOS Technology’s Quick Agent (V2 and V3) has been disclosed, allowing remote unauthenticated attackers to execute arbitrary code on Windows systems with system privileges. The flaw, rated 8.1 (HIGH) on the CVSS scale, was publicly documented on April 28, 2025, alongside two additional vulnerabilities in the same product1.
Executive Summary for Security Leaders
The vulnerability stems from improper pathname validation (CWE-22), enabling attackers to bypass directory restrictions. Successful exploitation grants full system control on affected Quick Agent installations. SIOS Technology has released patches (V2 ≥2.9.8, V3 ≥3.2.1) addressing all three vulnerabilities disclosed this week2.
- Risk: High (CVSS 8.1 for CVE-2025-26692)
- Affected: Quick Agent V2 before 2.9.8, V3 before 3.2.1
- Impact: Remote code execution without authentication
- Mitigation: Immediate patching or network segmentation
Technical Analysis
The path traversal vulnerability occurs when processing file uploads, where insufficient validation allows attackers to reference parent directories using “../” sequences. This can lead to arbitrary file writes in system directories, subsequently enabling remote code execution. The attack vector is network-based and requires no authentication, making it particularly dangerous for exposed systems3.
Two related vulnerabilities were disclosed simultaneously:
| CVE | Type | CVSS | Impact |
|---|---|---|---|
| CVE-2025-27937 | Path Traversal | 4.9 | Authenticated file read |
| CVE-2025-31144 | Access Control | 6.9 | Arbitrary host login attempts |
Detection and Response
Organizations should scan for Quick Agent installations and verify versions. The following indicators may suggest exploitation attempts:
“Look for unusual file creation in system directories, particularly from Quick Agent processes. Monitor for unexpected child processes spawned by the Quick Agent service.”1
Network-based detection can focus on anomalous file paths in HTTP requests to Quick Agent endpoints. SIEM rules should alert on sequences containing “../” or attempts to access known system files through the agent interface.
Remediation Guidance
SIOS Technology recommends upgrading to the latest patched versions. For environments where immediate patching isn’t feasible, implement these temporary measures:
- Restrict Quick Agent network access to trusted IPs only
- Block inbound connections to Quick Agent ports from untrusted networks
- Apply strict file system permissions to Quick Agent installation directories
The vendor advisory provides additional hardening guidance for Japanese-speaking users2.
Conclusion
CVE-2025-26692 represents a significant risk to organizations using vulnerable Quick Agent versions. The combination of remote exploitability and high-privilege access warrants urgent attention. This vulnerability follows a pattern of increasing path traversal flaws across enterprise software, as seen in recent Spring Framework and Ping Identity advisories3.
Security teams should prioritize inventorying Quick Agent deployments and applying vendor patches. Continuous monitoring for anomalous file system activity on affected systems is recommended even after patching.
References
- “Multiple Vulnerabilities in SIOS Technology Quick Agent,” Cybersecurity Help, 2025-04-25.
- “SIOS Technology Quick Agent Security Advisory,” (Japanese), 2025-04-25.
- “JVN#82536398: SIOS Quick Agent vulnerabilities,” JVN, 2025-04-25.
