CWE-1386: Insecure Operation on Windows Junction / Mount… | Glexia
CWE-1386 (Insecure Operation on Windows Junction / Mount Point) weakness overview with consequences, detection methods, mitigations, related CVEs and MITRE ATT&CK…
Glexia's Take · Automated analysis
CWE-1386: Insecure Operation on Windows Junction / Mount Point
Insecure Operation on Windows Junction / Mount Point represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Confidentiality: Read Files or Directories: Read arbitrary files by replacing a user-controlled folder with a mount point and additional hard links.
- Integrity: Modify Files or Directories: Modify an arbitrary file by replacing the rollback files in installer directories, as they can have the installer execute those rollbacks.
- Availability: Modify Files or Directories: Even if there is no control of contents, an arbitrary file delete or overwrite (when running as SYSTEM or admin) can be used for a permanent system denial-of-service, e.g. by deleting a startup configuration file that prevents the service from starting.
Developer Pattern
CWE-1386 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-1386, 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-1386: Insecure Operation on Windows Junction / Mount Point
The product opens a file or directory, but it does not properly prevent the name from being associated with a junction or mount point to a destination that is outside of the intended control sphere.
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: When designing software that will have different rights than the executer, the software should check that files that it is interacting with are not improper hard links or mount points. One way to do this in Windows is to use the functionality embedded in the following command: "dir /al /s /b" or, in PowerShell, use LinkType as a filter. In addition, some software uses authentication via signing to ensure that the file is the correct one to use. Make checks atomic with the file action, otherwise a TOCTOU weakness (CWE-367) can be introduced.
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.