helmetjs/csp · Security
Configuration Override in helmet-csp
- GHSA ID
- GHSA-c3m8-x3cg-qm2c
- Severity
- medium
- Published
- Updated
- CVSS
- 6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CVSS v3
- 6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Description
Versions of helmet-csp before to 2.9.1 are vulnerable to a Configuration Override affecting the application's Content Security Policy (CSP). The package's browser sniffing for Firefox deletes the default-src CSP policy, which is the fallback policy. This allows an attacker to remove an application's default CSP, possibly rendering the application vulnerable to Cross-Site Scripting.
Recommendation
Upgrade to version 2.9.1 or later. Setting the browserSniff configuration to false in vulnerable versions also mitigates the issue.