Weakness · High
CWE-641: Improper Restriction of Names for Files and Other Resources
What it is
The product constructs the name of a file or other resource using input from an upstream component, but it does not restrict or incorrectly restricts the resulting name.
- Severity (our rating)
- High
- Likelihood of exploit
- Low
- Introduced during
- Architecture and Design, Implementation
- Exploited in the wild
- 1 known exploited CVE
In more detail
This may produce resultant weaknesses. For instance, if the names of these resources contain scripting characters, it is possible that a script may get executed in the client's browser if the application ever displays the name of the resource on a dynamically generated web page. Alternately, if the resources are consumed by some application parser, a specially crafted name can exploit some vulnerability internal to the parser, potentially resulting in execution of arbitrary code on the server machine. The problems will vary based on the context of usage of such malformed resource names and whether vulnerabilities are present in or assumptions are made by the targeted technology that would make code execution possible.
What an attacker can do
- Execute Unauthorized Code or Commands (Integrity, Confidentiality, Availability)
- Read Application Data (Confidentiality, Availability)
- DoS: Crash, Exit, or Restart (Confidentiality, Availability)
How to prevent it
Architecture and Design
- Do not allow users to control names of resources used on the server side.
- Perform allowlist input validation at entry points and also before consuming the resources. Reject bad file names rather than trying to cleanse them.
- Make sure that technologies consuming the resources are not vulnerable (e.g. buffer overflow, format string, etc.) in a way that would allow code execution if the name of the resource is malformed.
Exploited in the wild: 1 CVE
Vulnerabilities caused by CWE-641 that attackers have used, from CISA's Known Exploited Vulnerabilities catalog, newest first.
H2 Security
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.