CVE-2020-5216 Limited header injection when using dynamic overrides with user input in RubyGems secure_headers
Attackers can inject newlines into Content-Security-Policy headers via user input, bypassing security restrictions in Ruby applications using the secure_headers gem.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2020-5216?
CVE-2020-5216 is a medium-severity vulnerability in Twitter secure_headers, published on 23 Jan 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
In Secure Headers (RubyGem secure_headers), a directive injection vulnerability is present in versions before 3.9.0, 5.2.0, and 6.3.0. If user-supplied input was passed into append/override_content_security_policy_directives, a newline could be injected leading to limited header injection. Upon seeing a newline in the header, rails will silently create a new Content-Security-Policy header with the remaining value of the original string. It will continue to create new headers for each newline. This has been fixed in 6.3.0, 5.2.0, and 3.9.0.
Which versions are affected by CVE-2020-5216?
6 open source packages ship an affected version, including secure_headers. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
secure_headers RubyGems | All versions | 3.9.0 |
secure_headers RubyGems | All versions | 3.9.0 |
secure_headers RubyGems | From 5.0.0 | 5.2.0 |
secure_headers RubyGems | From 5.0.0 | 5.2.0 |
secure_headers RubyGems | From 6.0.0 | 6.3.0 |
secure_headers RubyGems | From 6.0.0 | 6.3.0 |
Products include Twitter Secure Headers.
How do I fix CVE-2020-5216?
Upgrade secure_headers to a fixed version for your release line: 3.9.0, 5.2.0 or 6.3.0.
Is CVE-2020-5216 being exploited?
There is no known exploitation of CVE-2020-5216 in the wild and no public exploit code.
Other vulnerabilities in Twitter secure_headers
Sources
Also known as DEBIAN-CVE-2020-5216, GHSA-w978-rmpf-qmwg, UBUNTU-CVE-2020-5216.