CVE-2020-5247

MEDIUM severity · CVSS 6.5 · CWE-113

6.5CVSS MEDIUM

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredLow

User interactionRequired

Confidentiality impactLow

Integrity impactLow

Availability impactLow

Exploit probability (EPSS)2%

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L

Affected products we track (1)

Ruby

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

CVE-2020-5247

Summary

Impact & exploitability

Affected products we track (1)

Recommendation

Additional information