Vulnerability · Published Dec 7, 2022 · Assigned by Go
CVE-2022-41720Restricted file access on Windows in os and net/http
High 7.5
In plain English
A high-severity security flaw in net/http from Go standard library. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 70% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
On Windows, restricted files can be accessed via os.DirFS and http.Dir. The os.DirFS function and http.Dir type provide access to a tree of files rooted at a given directory. These functions permit access to Windows device files under that root. For example, os.DirFS("C:/tmp").Open("COM1") opens the COM1 device. Both os.DirFS and http.Dir only provide read-only filesystem access. In addition, on Windows, an os.DirFS for the directory (the root of the current drive) can permit a maliciously crafted path to escape from the drive and access any path on the system. With fix applied, the behavior of os.DirFS("") has changed. Previously, an empty root was treated equivalently to "/", so os.DirFS("").Open("tmp") would open the path "/tmp". This now returns an error.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-1.19 | 1.19.4-1 | DEBIAN-CVE-2022-41720 |
| Go | stdlib | 1.18.9, 1.19.4 | GO-2022-1143 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Go standard library | os | 0 – before 1.18.91.19.0-0 – before 1.19.4 |
| Go standard library | net/http | 0 – before 1.18.91.19.0-0 – before 1.19.4 |