CVE-2025-27937: Quick Agent Path Traversal Vulnerability

CVE-2025-27937 Overview

CVE-2025-27937 is a path traversal vulnerability affecting SIOS Quick Agent V3 and Quick Agent V2. The flaw stems from improper limitation of a pathname to a restricted directory, classified as [CWE-22]. An authenticated remote attacker can exploit the issue to retrieve arbitrary files from the affected product.

The vulnerability requires the attacker to first log in to the product. Once authenticated, the attacker can supply crafted pathname input to access files outside the intended directory scope. This exposes sensitive configuration data, credentials, and other host-resident files to unauthorized read access.

Critical Impact
Authenticated remote attackers can read arbitrary files from systems running Quick Agent V2 or V3, exposing sensitive host data.

Affected Products

SIOS Quick Agent V3
SIOS Quick Agent V2

Discovery Timeline

2025-04-28 - CVE-2025-27937 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-27937

Vulnerability Analysis

CVE-2025-27937 is a path traversal weakness in the file-handling logic of Quick Agent V2 and V3. The product accepts pathname input from authenticated users without adequately restricting traversal sequences such as ../. An attacker who supplies these sequences can escape the intended directory and access files elsewhere on the file system.

Because the flaw exposes file contents rather than modifying data or triggering code execution, the primary impact is confidentiality loss. Files readable by the Quick Agent service account become reachable through the exposed interface. This can include system configuration, application logs, and secrets used by adjacent services.

The attacker must hold valid product credentials to reach the vulnerable endpoint. The barrier is therefore any authenticated principal, including low-privileged users, insider threats, and attackers who have obtained credentials through phishing or reuse.

Root Cause

The root cause is insufficient validation and canonicalization of user-supplied file paths. The product does not reject or normalize traversal sequences before resolving the path against the underlying file system. This is a classic manifestation of [CWE-22]: Improper Limitation of a Pathname to a Restricted Directory.

Attack Vector

Attackers deliver the exploit over the network to an authenticated session. Crafted requests containing directory traversal payloads target file-serving or file-retrieval functions in the Quick Agent web interface or API. The vulnerability requires no user interaction beyond attacker-initiated authenticated requests.

The vulnerability is described in the JVN #82536398 Advisory and the SIOS Agent Information Update. Refer to the vendor materials for endpoint-level technical detail.

Detection Methods for CVE-2025-27937

Indicators of Compromise

Requests to Quick Agent endpoints containing ../, ..\, or URL-encoded variants such as %2e%2e%2f in path or query parameters.
Access log entries showing file retrieval calls that reference paths outside the Quick Agent installation directory.
Unusual read access to sensitive files such as /etc/passwd, application configuration files, or credential stores by the Quick Agent service account.

Detection Strategies

Inspect Quick Agent HTTP access logs for traversal patterns and encoded traversal sequences in file-related parameters.
Correlate authentication events with file-retrieval requests to identify low-privileged accounts pulling sensitive files.
Deploy web application firewall or intrusion detection signatures that match traversal payloads targeting Quick Agent endpoints.

Monitoring Recommendations

Enable verbose request logging on Quick Agent V2 and V3 instances until patched systems are verified.
Monitor file system audit logs for reads issued by the Quick Agent service against paths outside its expected working directory.
Alert on repeated 200-status file retrievals from a single authenticated session in short time windows.

How to Mitigate CVE-2025-27937

Immediate Actions Required

Apply the vendor-supplied updates referenced in the SIOS Support Article and SIOS Agent Information Update.
Rotate credentials for all Quick Agent user accounts and any secrets that may have been exposed through file reads.
Restrict network access to Quick Agent management interfaces to trusted administrative networks only.

Patch Information

SIOS has published fix information through the vendor advisories linked above. Administrators should consult the JVN #82536398 Advisory for authoritative version and remediation guidance for Quick Agent V2 and V3.

Workarounds

Limit authenticated access to Quick Agent to a minimal set of trusted administrators until patches are applied.
Place Quick Agent behind a reverse proxy or web application firewall that filters directory traversal sequences in request paths and parameters.
Run the Quick Agent service under a least-privileged account so exposed file reads are constrained by file system permissions.

bash

# Configuration example: WAF rule concept to block traversal payloads
# Reject requests containing common traversal sequences before reaching Quick Agent
SecRule REQUEST_URI|ARGS "@rx (\.\./|\.\.\\|%2e%2e%2f|%2e%2e/|\.\.%2f)" \
    "id:1002700,phase:2,deny,status:403,msg:'Path traversal blocked (CVE-2025-27937)'"