CVE-2021-32773 Confused deputy attack in sandbox module resolution
Attackers can hijack system module resolution in the Racket sandbox to execute arbitrary code and bypass security restrictions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-32773?
CVE-2021-32773 is a medium-severity code injection vulnerability in racket, published on 19 Jul 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Racket is a general-purpose programming language and an ecosystem for language-oriented programming. In versions prior to 8.2, code evaluated using the Racket sandbox could cause system modules to incorrectly use attacker-created modules instead of their intended dependencies. This could allow system functions to be controlled by the attacker, giving access to facilities intended to be restricted. This problem is fixed in Racket version 8.2. A workaround is available, depending on system settings. For systems that provide arbitrary Racket evaluation, external sandboxing such as containers limit the impact of the problem. For multi-user evaluation systems, such as the `handin-server` system, it is not possible to work around this problem and upgrading is required.
Which versions are affected by CVE-2021-32773?
It affects 1 product.
Products include Racket-Lang Racket.
How do I fix CVE-2021-32773?
Upgrade to a fixed version.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2021-32773 being exploited?
There is no known exploitation of CVE-2021-32773 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2021-32773, GHSA-cgrw-p7p7-937c, UBUNTU-CVE-2021-32773.