CVE-2021-21125

Insufficient policy enforcement in File System API in Google Chrome on Windows prior to 88.0.4324.96 allowed a remote attacker to bypass filesystem restrictions via a crafted HTML page.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• https://chromereleases.googleblog.com/2021/01/stable-channel-update-for-desktop_19.html
• https://crbug.com/1152327
• https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-21125
• https://chromereleases.googleblog.com/2021/01/stable-channel-update-for-desktop_19.html
• https://crbug.com/1152327
• https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-21125