CVE-2020-5247
6.5 · MEDIUMOverview
CVE-2020-5247 is a medium-severity vulnerability affecting puma puma. It was published on February 28, 2020 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
In Puma (RubyGem) before 4.3.2 and before 3.12.3, if an application using Puma allows untrusted input in a response header, an attacker can use newline characters (i.e. `CR`, `LF` or`/r`, `/n`) to end the header and inject malicious content, such as additional headers or an entirely new response body. This vulnerability is known as HTTP Response Splitting. While not an attack in itself, response splitting is a vector for several other attacks, such as cross-site scripting (XSS). This is related to CVE-2019-16254, which fixed this vulnerability for the WEBrick Ruby web server. This has been fixed in versions 4.3.2 and 3.12.3 by checking all headers for line endings and rejecting headers with those characters.
Remediation
Check the references section for vendor advisories and patches from puma. Update puma to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| puma | puma | 0 | Affected |
| ruby-lang | ruby | 0 | Affected |
References
Frequently Asked Questions
What is CVE-2020-5247?
CVE-2020-5247 is a medium-severity vulnerability affecting puma puma. It was published on February 28, 2020 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
How severe is CVE-2020-5247?
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2020-5247?
Check the references section for vendor advisories and patches from puma. Update puma to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2020-5247?
CyberStrike's AI-powered security agents can automatically detect CVE-2020-5247 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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