CVE-2020-25032 Flask-Cors Directory Traversal vulnerability

High 7.5 Published 31 Aug 2020 Updated 4 Aug 2024

Attackers can use directory traversal to access private resources in applications using the Flask-CORS library.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2020-25032?

CVE-2020-25032 is a high-severity path traversal vulnerability in Debian Debian Linux, published on 31 Aug 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered in Flask-CORS (aka CORS Middleware for Flask) before 3.0.9. It allows ../ directory traversal to access private resources because resource matching does not ensure that pathnames are in a canonical format.

Weakness: CWE-22

Which versions are affected by CVE-2020-25032?

3 open source packages ship an affected version, including flask-cors and Flask-Cors. It affects 4 products.

Package	Affected	Fixed in
`flask-cors` PyPI	All versions	`3.0.9`
`flask-cors` PyPI	All versions	`3.0.9`
`Flask-Cors` PyPI	All versions	`3.0.9`

Linux distribution packages (7)

`python-Flask-Cors` SUSE:Package Hub 15 SP1	All versions	`3.0.7-bp151.2.3.1`
`python-Flask-Cors` SUSE:Package Hub 15 SP2	All versions	`3.0.8-bp152.2.3.1`
`python-Flask-Cors` SUSE:Package Hub 15 SP2	All versions	`3.0.8-bp152.2.3.1`
`python-Flask-Cors` openSUSE:Leap 15.1	All versions	`3.0.8-lp152.2.3.1`
`python-Flask-Cors` openSUSE:Leap 15.2	All versions	`3.0.8-lp152.2.3.1`
`python-Flask-Cors` openSUSE:Tumbleweed	All versions	`3.0.10-1.3`
`python-Flask-Cors` openSUSE:Tumbleweed	All versions	`4.0.0-1.3`

Products include Debian Debian Linux, Flask-Cors Project Flask-Cors, Opensuse Backports Sle, Opensuse Leap.

How do I fix CVE-2020-25032?

Upgrade flask-cors to 3.0.9 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2020-25032 being exploited?

There is no known exploitation of CVE-2020-25032 in the wild and no public exploit code.

All Debian Debian Linux vulnerabilities

Sources

Also known as DEBIAN-CVE-2020-25032, DSA-4775-1, GHSA-xc3p-ff3m-f46v, PYSEC-2020-43, UBUNTU-CVE-2020-25032, USN-6019-1 and 6 more.