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GHSA-2hfj-cxw7-g45p

HighCVSS 8.2 / 10
Published Dec 14, 2021·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

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:

Risk Scores
Base Score
8.2

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a low impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a low impact on the availability of the system.

Threat Intelligence
7.5

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.75%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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