CVE-2020-5217

Description

In Secure Headers (RubyGem secure_headers), a directive injection vulnerability is present in versions before 3.8.0, 5.1.0, and 6.2.0. If user-supplied input was passed into append/override_content_security_policy_directives, a semicolon could be injected leading to directive injection. This could be used to e.g. override a script-src directive. Duplicate directives are ignored and the first one wins. The directives in secure_headers are sorted alphabetically so they pretty much all come before script-src. A previously undefined directive would receive a value even if SecureHeaders::OPT_OUT was supplied. The fixed versions will silently convert the semicolons to spaces and emit a deprecation warning when this happens. This will result in innocuous browser console messages if being exploited/accidentally used. In future releases, we will raise application errors resulting in 500s. Depending on what major version you are using, the fixed versions are 6.2.0, 5.1.0, 3.8.0.

Weakness classification

• security-advisories@github.com: CWE-95
• nvd@nist.gov: CWE-74

Primary references

• security-advisories@github.com — Patch
• security-advisories@github.com — Exploit, Third Party Advisory
• security-advisories@github.com — Third Party Advisory
• security-advisories@github.com — Mitigation, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Patch
• af854a3a-2127-422b-91ae-364da2661108 — Exploit, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Mitigation, Third Party Advisory