vulnerability / NVI-00018575 / Revision 1
Dozzle's Cross-Site WebSocket Hijacking (CSWSH) on exec/attach endpointsbypasses authentication
GitHub lists this reviewed advisory for github.com/amir20/dozzle. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
9.6 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/amir20/dozzle
source listed<= 10.5.1
## Summary The WebSocket upgrader for the `/exec` and `/attach` endpoints uses `CheckOrigin: func(r *http.Request) bool { return true }`, accepting upgrade requests from any origin. Combined with the JWT cookie using `SameSite: Lax`, this enables Cross-Site WebSocket Hijacking (CSWSH) — **even when authentication is properly configured**. An attacker hosting a page on a same-site origin (e.g., a sibling subdomain, or another service on localhost) can initiate a WebSocket connection to the exec endpoint that carries the victim's valid JWT cookie, gaining interactive shell access in any container the victim is authorized to access. ## Root cause **1. CheckOrigin bypassed (`internal/web/terminal.go:15-21`)** ```go var upgrader = websocket.Upgrader{ ReadBufferSize: 1024, WriteBufferSize: 1024, CheckOrigin: func(r *http.Request) bool { return true }, } ``` The gorilla/websocket default CheckOrigin rejects cross-origin requests. Overriding it to return `true` removes the only server-side defense against CSWSH. **2. JWT cookie with SameSite=Lax (`internal/web/auth.go:20-27`)** ```go http.SetCookie(w, &http.Cookie{ Name: "jwt", Value: token,
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-j643-x8pv-8m67 ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.