{"id":"CVE-2026-33766","aliases":["GHSA-f359-r3pv-2phf"],"url":"https://o3.security/vulnerability/CVE-2026-33766","summary":"AVideo has SSRF Protection Bypass via HTTP Redirect in Image Download Endpoints","details":"## Summary\n\n`isSSRFSafeURL()` validates URLs against private/reserved IP ranges before fetching, but `url_get_contents()` follows HTTP redirects without re-validating the redirect target. An attacker can bypass SSRF protection by redirecting from a public URL to an internal target.\n\n## Root Cause\n\n**Check-time:** `isSSRFSafeURL()` at `objects/functions.php:4066` resolves the hostname and validates the IP.\n\n**Use-time:** `url_get_contents()` at `objects/functions.php:1990` calls `file_get_contents()` with PHP's default `follow_location=1` — redirects are followed without re-validation. The wget fallback at line 2047 also follows redirects by default.\n\n**Affected endpoint:** `objects/aVideoEncoderReceiveImage.json.php` at lines 67-68, 107-108, 135-136, 160-161:\n```php\nif (isValidURL($_REQUEST['downloadURL_image']) && isSSRFSafeURL($_REQUEST['downloadURL_image'])) {\n    $content = url_get_contents($_REQUEST['downloadURL_image']);\n```\n\n## Proof of Concept\n\n1. Attacker sets up `https://attacker.com/redir` to respond with `302 Location: http://169.254.169.254/latest/meta-data/`\n2. Authenticated user (with upload+edit permissions) triggers image download:\n```\nGET /objects/aVideoEncoderReceiveImage.json.php?downloadURL_image=https://attacker.com/redir&...\n```\n3. `isSSRFSafeURL()` resolves `attacker.com` → public IP → passes validation\n4. `url_get_contents()` follows 302 redirect to `169.254.169.254` → SSRF\n\n## Impact\n\n- Cloud metadata access (AWS IMDSv1, GCP, Azure)\n- Internal network service access\n- Bypasses the existing SSRF protection that was added to prevent exactly this class of attack\n\n## Note\n\nThe curl path in `url_get_contents()` does NOT set `CURLOPT_FOLLOWLOCATION` so it is not affected. Only the `file_get_contents` and `wget` fallback paths are vulnerable.\n\n## Suggested Fix\n\nSet `follow_location` to `0` in the stream context and handle redirects manually with re-validation, or add `isSSRFSafeURL()` check inside `url_get_contents()` after resolving the final URL.","published":"2026-03-27T14:31:06.272Z","modified":"2026-08-12T03:51:43.264176907Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Packagist","name":"wwbn/avideo","fixedVersion":null}],"fix":{"url":"https://github.com/WWBN/AVideo/commit/8b7e9dad359d5fac69e0cbbb370250e0b284bc12","label":"WWBN/AVideo@8b7e9da"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33766.json"},{"type":"ADVISORY","url":"https://github.com/WWBN/AVideo/security/advisories/GHSA-f359-r3pv-2phf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33766"},{"type":"FIX","url":"https://github.com/WWBN/AVideo/commit/8b7e9dad359d5fac69e0cbbb370250e0b284bc12"},{"type":"PACKAGE","url":"https://github.com/WWBN/AVideo"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:43.264176907Z"}}