CVE-2021-48011

Received Received - Intake

Path Traversal in Servor Web Server

Publication date: 2026-10-12

Last updated on: 2026-10-12

Assigner: VulnCheck

Description

Servor 1.0.0 through 4.0.2 contains a path traversal vulnerability that allows unauthenticated remote attackers to escape the served root by sending URL-encoded dot segments. Attackers can send %2e%2e/ sequences, which decodeURI() decodes before path.join() in serveStaticFile and serveDirectoryListing, to read arbitrary files and list directories outside the root.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-12

Last Modified

2026-10-12

Generated

2026-10-13

AI Q&A

2026-10-13

EPSS Evaluated

N/A

NVD

CVE-2021-48011

Affected Vendors & Products

Vendor	Product	Version / Range
lukejacksonn	servor	1.0.0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-22	The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Attack-Flow Graph

Executive Summary

This vulnerability is a path traversal issue in Servor versions 1.0.0 through 4.0.2. It allows unauthenticated remote attackers to escape the intended root directory by sending URL-encoded dot segments like %2e%2e/. The decodeURI() function decodes these sequences before path.join() processes them in serveStaticFile and serveDirectoryListing functions, enabling attackers to read arbitrary files or list directories outside the intended root.

Detection Guidance

To detect this vulnerability, check if your system is running Servor versions 1.0.0 through 4.0.2. Test by sending URL-encoded dot sequences like %2e%2e/ to see if arbitrary files or directories outside the root can be accessed.

Impact Analysis

This vulnerability can allow attackers to access sensitive files on your server, including configuration files, source code, or other confidential data. If exploited, it could lead to unauthorized information disclosure, potential data breaches, or further attacks against your system.

Compliance Impact

This vulnerability could lead to non-compliance with GDPR, HIPAA, or other regulations by exposing sensitive personal or health data. Unauthorized file access may result in data breaches, triggering legal penalties, fines, or reputational damage for failing to protect confidential information.

Mitigation Strategies

Immediately upgrade Servor to a version beyond 4.0.2 if available. If not, disable or remove Servor from your system. Implement network-level restrictions to block malicious requests containing %2e%2e/ sequences.

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