CVE-2020-5216Limited header injection when using dynamic overrides with user input in RubyGems secure_headers
- 4.4MediumCVSS base score
- 1.2%Exploitation in 30 daysEPSS · top 31% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By GitHub_M
- 21 days later
· 21 days later
Published
- 5 years later
· 5 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium4.4 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVDNVD · Modified | 3.1 | Medium5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 1.2% · top 31% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.4.
Affected products
- affected < 3.9.0
- affected >= 5.0.0, < 5.2.0
- affected >= 6.0.0, < 6.3.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemssecure_headersGHSA-w978-rmpf-qmwg (opens in a new tab)
References
References2
- https://github.com/twitter/secure_headers/security/advisories/GHSA-w978-rmpf-qmwg (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/twitter/secure_headers/commit/301695706f6a70517c2a90c6ef9b32178440a2d0 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2020-0281 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-w978-rmpf-qmwg (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-5216)Record last updated .