CWE-641: Improper Restriction of Names for Files and… | Glexia
CWE-641 (Improper Restriction of Names for Files and Other Resources) weakness overview with consequences, detection methods, mitigations, related CVEs and MITRE…
Glexia's Take · Automated analysis
CWE-641: Improper Restriction of Names for Files and Other Resources
Improper Restriction of Names for Files and Other Resources represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Integrity,Confidentiality,Availability: Execute Unauthorized Code or Commands: Execution of arbitrary code in the context of usage of the resources with dangerous names.
- Confidentiality,Availability: Read Application Data,DoS: Crash, Exit, or Restart: Crash of the consumer code of these resources resulting in information leakage or denial of service.
Developer Pattern
CWE-641 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Automation confidence
high confidence from CWE-641, 4.20.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Official CWE Definition
CWE-641: Improper Restriction of Names for Files and Other Resources
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.
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.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- Missing validation
- Unsafe defaults
- Insufficient authorization or memory-safety invariant
Remediation
- Architecture and Design: Do not allow users to control names of resources used on the server side.
- Architecture and Design: Perform allowlist input validation at entry points and also before consuming the resources. Reject bad file names rather than trying to cleanse them.
- Architecture and Design: 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.
Detection
- Code review
- SAST
- DAST
- Focused regression tests
Mappings
Related CVEs, CWEs, and ATT&CK context
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.