{"id":"PYSEC-2026-3904","summary":"praisonaiagents vulnerable to SSRF in web_crawl tool via redirect-following and DNS rebinding (validate-then-fetch gap)","details":"The web_crawl tool performs its SSRF check only on the initial URL: it resolves the hostname once\nwith socket.gethostbyname and rejects private/loopback/link-local results. It then passes the URL to\na fetcher that uses httpx.Client(follow_redirects=True) - or urllib.request.urlopen when httpx is\nabsent, which also follows redirects - and re-resolves the hostname at connect time, with no further\nvalidation. This validate-here/fetch-there gap is bypassable two independent ways: HTTP redirects and\nDNS rebinding.\n\nAffected code: src/praisonai-agents/praisonaiagents/tools/web_crawl_tools.py\n- Single-shot validation (lines 229-238):\n    if os.environ.get(\"ALLOW_LOCAL_CRAWL\") != \"true\":\n        ip_str = socket.gethostbyname(hostname)            # resolved ONCE, at validation time\n        ip = ipaddress.ip_address(ip_str)\n        if ip.is_loopback or ip.is_private or ip.is_link_local or ip.is_multicast or ip.is_unspecified:\n            continue                                       # rejected\n    url_list.append(u)\n- Vulnerable fetch (_crawl_with_httpx, lines 142 / 149): follows redirects, re-resolves DNS, no re-check:\n    with httpx.Client(follow_redirects=True, timeout=30.0) as client: response = client.get(url)\n    # fallback: urllib.request.urlopen(url, timeout=30)  (also follows redirects by default)\n- web_crawl / crawl_web are registered tools (tools/__init__.py:156-157); httpx is the default fallback\n  provider (dispatch at web_crawl_tools.py:269).\n\nThe two bypasses:\n1) Redirect: validation approves an attacker domain resolving to a public IP; attacker server replies\n   302 Location: http://169.254.169.254/... (or any internal host); the fetcher follows it unchecked.\n2) DNS rebinding (TOCTOU): validator's gethostbyname and fetcher's connect-time resolution are\n   independent; a low-TTL attacker domain answers public to the validator and private/loopback to fetch.\n\nImpact:\nAn agent with web_crawl - driven by direct input or indirect prompt injection - can be made to read\ninternal-only HTTP services and cloud instance-metadata endpoints (e.g. IAM credentials), with the\nresponse body returned in the tool output. Scope is Changed because the request pivots into the\ninternal network.\n\nProof of concept:\nA PoC drives the real web_crawl() (httpx absent -\u003e genuine urllib fallback). It runs a loopback\n\"internal metadata\" service and a loopback attacker redirector, substituting DNS only to stand in\nfor \"attacker owns a public domain\" / offline routing - the redirect-following and connect-time\nre-resolution are the repo's own behavior. Observed:\n  CONTROL: web_crawl(\"http://127.0.0.1:.../meta-data/\")  -\u003e blocked (validator works)\n  PoC 1A (redirect):  attacker.example approved (public); 302 -\u003e loopback metadata\n                      -\u003e result.content leaks {\"AccessKeyId\":\"ASIA_FAKE_STOLEN_CREDENTIAL_...\"}\n  PoC 1B (rebinding): gethostbyname(rebind.example)-\u003epublic (allowed); connect-\u003e127.0.0.1\n                      -\u003e same secret leaked\nThe control proves the validator blocks a direct loopback request, so the bypasses are genuine.\n\nRemediation:\nResolve the hostname once, validate that IP, and connect to that exact validated IP (pin it) rather\nthan re-resolving. Disable redirect following (follow_redirects=False; for urllib use a redirect\nhandler that re-validates), or re-validate every redirect hop's resolved IP. Apply the deny check to\nboth the validator and the actual socket target. file_tools.py:364 already uses follow_redirects=False\nand is the correct pattern to propagate.\n\nDistinct from prior advisories:\nThe accepted SSRF advisories concern host-string parsing in different code — alternate loopback\nencodings in spider_tools (GHSA-5c6w-wwfq-7qqm) and the CLI @url feature (GHSA-5cxw-77wg-jrf3). This\nis in the web_crawl tool, which neither advisory names, and the mechanisms (redirect-following and DNS\nrebinding) differ categorically from host-string encoding; the spider_tools _host_is_blocked hardening\ndoes not apply to this tool.","aliases":["CVE-2026-55524","GHSA-vg6p-v9vm-6fgj"],"modified":"2026-09-10T12:15:11.255794100Z","published":"2026-09-10T09:44:54.383774Z","references":[{"type":"WEB","url":"https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-vg6p-v9vm-6fgj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55524"},{"type":"WEB","url":"https://github.com/MervinPraison/PraisonAI/commit/2f9677abb2ea68eab864ee8b6a828fd0141612e1"},{"type":"PACKAGE","url":"https://github.com/MervinPraison/PraisonAI"},{"type":"WEB","url":"https://github.com/MervinPraison/PraisonAI/releases/tag/v4.6.58"},{"type":"PACKAGE","url":"https://pypi.org/project/praisonaiagents"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-vg6p-v9vm-6fgj"}],"affected":[{"package":{"name":"praisonaiagents","ecosystem":"PyPI","purl":"pkg:pypi/praisonaiagents"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.58"}]}],"versions":["0.0.1","0.0.10","0.0.100","0.0.101","0.0.102","0.0.103","0.0.104","0.0.105","0.0.106","0.0.107","0.0.108","0.0.109","0.0.11","0.0.110","0.0.111","0.0.112","0.0.113","0.0.114","0.0.115","0.0.116","0.0.117","0.0.118","0.0.119","0.0.12","0.0.120","0.0.121","0.0.122","0.0.123","0.0.124","0.0.125","0.0.126","0.0.127","0.0.128","0.0.129","0.0.13","0.0.130","0.0.131","0.0.132","0.0.133","0.0.134","0.0.135","0.0.136","0.0.137","0.0.138","0.0.139","0.0.14","0.0.140","0.0.141","0.0.142","0.0.143","0.0.144","0.0.145","0.0.146","0.0.147","0.0.148","0.0.149","0.0.15","0.0.150","0.0.151","0.0.152","0.0.153","0.0.154","0.0.155","0.0.156","0.0.157","0.0.158","0.0.159","0.0.16","0.0.160","0.0.161","0.0.162","0.0.163","0.0.164","0.0.165","0.0.166","0.0.167","0.0.168","0.0.169","0.0.17","0.0.170","0.0.171","0.0.172","0.0.173","0.0.174","0.0.175","0.0.176","0.0.177","0.0.178","0.0.179","0.0.18","0.0.180","0.0.181","0.0.182","0.0.183","0.0.184","0.0.185","0.0.187","0.0.188","0.0.189","0.0.19","0.0.190","0.0.191","0.0.192","0.0.193","0.0.194","0.0.195","0.0.196","0.0.197","0.0.198","0.0.199","0.0.2","0.0.20","0.0.21","0.0.22","0.0.23","0.0.24","0.0.25","0.0.26","0.0.27","0.0.28","0.0.29","0.0.3","0.0.30","0.0.31","0.0.32","0.0.33","0.0.34","0.0.35","0.0.36","0.0.37","0.0.38","0.0.39","0.0.4","0.0.40","0.0.41","0.0.42","0.0.43","0.0.44","0.0.45","0.0.46","0.0.47","0.0.48","0.0.49","0.0.5","0.0.50","0.0.51","0.0.52","0.0.53","0.0.54","0.0.56","0.0.57","0.0.58","0.0.59","0.0.6","0.0.60","0.0.61","0.0.62","0.0.63","0.0.64","0.0.65","0.0.66","0.0.67","0.0.68","0.0.69","0.0.7","0.0.70","0.0.71","0.0.72","0.0.73","0.0.74","0.0.75","0.0.76","0.0.77","0.0.78","0.0.79","0.0.8","0.0.80","0.0.81","0.0.82","0.0.83","0.0.84","0.0.85","0.0.86","0.0.87","0.0.88","0.0.89","0.0.9","0.0.90","0.0.91","0.0.92","0.0.93","0.0.94","0.0.95","0.0.96","0.0.97","0.0.98","0.0.99","0.1.0","0.1.1","0.1.10","0.1.11","0.1.12","0.1.13","0.1.14","0.1.15","0.1.16","0.1.17","0.1.18","0.1.19","0.1.2","0.1.20","0.1.21","0.1.22","0.1.23","0.1.24","0.1.25","0.1.26","0.1.27","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.10.0","0.10.1","0.10.10","0.10.2","0.10.3","0.10.4","0.10.5","0.10.6","0.10.7","0.10.8","0.10.9","0.11.0","0.11.1","0.11.10","0.11.11","0.11.12","0.11.13","0.11.14","0.11.15","0.11.16","0.11.17","0.11.18","0.11.19","0.11.2","0.11.20","0.11.21","0.11.22","0.11.23","0.11.24","0.11.25","0.11.27","0.11.28","0.11.29","0.11.3","0.11.30","0.11.31","0.11.4","0.11.5","0.11.6","0.11.7","0.11.8","0.11.9","0.12.0","0.12.1","0.12.10","0.12.11","0.12.12","0.12.13","0.12.14","0.12.15","0.12.16","0.12.17","0.12.18","0.12.19","0.12.2","0.12.20","0.12.21","0.12.3","0.12.4","0.12.5","0.12.6","0.12.7","0.12.8","0.12.9","0.13.0","0.13.1","0.13.10","0.13.11","0.13.12","0.13.13","0.13.14","0.13.15","0.13.16","0.13.17","0.13.18","0.13.19","0.13.2","0.13.20","0.13.21","0.13.22","0.13.23","0.13.3","0.13.4","0.13.5","0.13.6","0.13.7","0.13.8","0.13.9","0.14.0","0.14.1","0.14.10","0.14.11","0.14.12","0.14.14","0.14.15","0.14.16","0.14.2","0.14.3","0.14.4","0.14.5","0.14.6","0.14.7","0.14.8","0.14.9","0.15.0","0.15.1","0.15.2","0.15.3","0.2.0","0.2.1","0.2.2","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.4.0","0.4.1","0.5.0","0.5.1","0.5.2","0.5.3","0.6.0","0.6.1","0.6.2","0.6.3","0.6.4","0.6.5","0.6.6","0.6.7","0.6.8","0.7.0","0.7.1","0.8.0","0.8.1","0.9.0","0.9.1","1.0.0","1.1.0","1.2.0","1.2.1","1.2.2","1.2.3","1.2.4","1.3.0","1.3.1","1.4.0","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.4.8","1.5.0","1.5.1","1.5.10","1.5.100","1.5.101","1.5.102","1.5.103","1.5.104","1.5.105","1.5.106","1.5.107","1.5.108","1.5.109","1.5.11","1.5.110","1.5.111","1.5.112","1.5.113","1.5.114","1.5.115","1.5.116","1.5.117","1.5.118","1.5.119","1.5.12","1.5.120","1.5.121","1.5.122","1.5.123","1.5.124","1.5.125","1.5.126","1.5.127","1.5.128","1.5.129","1.5.13","1.5.130","1.5.131","1.5.132","1.5.133","1.5.134","1.5.135","1.5.136","1.5.137","1.5.138","1.5.139","1.5.14","1.5.140","1.5.141","1.5.142","1.5.143","1.5.144","1.5.145","1.5.146","1.5.147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