CVE-2020-5247
Description
A flaw was discovered in rubygem-puma, where it did not properly forbid untrusted input in a response header. This flaw allows an attacker with the ability to tamper with HTTP headers to insert a new-line and insert malicious content, allowing an HTTP response splitting, which exposes the risk of attacks such as cross-site scripting.
Statement
This issue affects the version of rubygem-puma shipped with Red Hat Gluster Storage 3, as it does not validate whether the header value could inject a CR or LF and inject their own HTTP response.
Red Hat CloudForms uses affected RubyGem Puma, however, it is not vulnerable since it does not have custom code enabling early hints, HTTP/2 support or way to return 103 response. A future update may fix affected RubyGem.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | 7.5 | 6.5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | None | Low |
| User Interaction | None | None | Required |
| Scope | Unchanged | Unchanged | Changed |
| Confidentiality | None | None | Low |
| Integrity Impact | High | High | Low |
| Availability Impact | None | None | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
Red Hat CVSS v3 Score Explanation
Red Hat products do not use early hint configuration which makes this attack complex to perform. Furthermore, to manipulate cookies through line feed an attacker need to have an access to the product.
Understanding the Weakness (CWE)
Integrity,Access Control
Technical Impact: Modify Application Data; Gain Privileges or Assume Identity
CR and LF characters in an HTTP header may give attackers control of the remaining headers and body of the message that the application intends to send/receive, as well as allowing them to create additional messages entirely under their control.
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