Ecosyste.ms: Advisories

Security Advisories: GSA_kwCzR0hTQS0yaGZqLWN4dzctZzQ1cM0bRg

Unsafe inline XSS in pasting DOM element into chat

Impact

Inline scripts are executed when Javascript is parsed via a paste action.

1. Open https://watch.owncast.online/
2. Copy and then paste <img src=null onerror=alert('hello')> into the
   chat field.
3. An alert should pop up.

Patches

    ⋮ 13 │    // Content security policy
    ⋮ 14 │    csp := []string{
    ⋮ 15 │        "script-src 'self' 'sha256-2HPCfJIJHnY0NrRDPTOdC7AOSJIcQyNxzUuut3TsYRY='",
    ⋮ 16 │        "worker-src 'self' blob:", // No single quotes around blob:
    ⋮ 17 │    }

Will be patched in 0.0.9 by blocking unsafe-inline Content Security Policy and specifying the script-src. The worker-src is required to be set to blob for the video player.

For more information

If you have any questions or comments about this advisory:

• Open an issue in owncast/owncast
• Email us at [email protected]

Permalink: https://github.com/advisories/GHSA-2hfj-cxw7-g45p
JSON: https://advisories.ecosyste.ms/api/v1/advisories/GSA_kwCzR0hTQS0yaGZqLWN4dzctZzQ1cM0bRg
Source: GitHub Advisory Database
Origin: Unspecified
Severity: High
Classification: General
Published: over 2 years ago
Updated: about 1 year ago

CVSS Score: 8.2
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:L

Identifiers: GHSA-2hfj-cxw7-g45p, CVE-2021-39183
References:

• https://github.com/owncast/owncast/security/advisories/GHSA-2hfj-cxw7-g45p
• https://nvd.nist.gov/vuln/detail/CVE-2021-39183
• https://github.com/advisories/GHSA-2hfj-cxw7-g45p

Repository: https://github.com/owncast/owncast
Blast Radius: 0.0

Affected Packages