PraisonAI spider_tools SSRF protection bypass via alternate loopback host encodings
Date: 2026-05
Affected: pip/PraisonAI, pip/praisonaiagents
Attack vector: ssrf
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-47390
CWE: CWE-918
CVSS: 5.5 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N)

### Summary PraisonAI's `spider_tools` URL validation can be bypassed using alternate loopback host encodings. The affected component is: ```text praisonaiagents/tools/spider_tools.py ```` The tool contains a URL validation function intended to block local or unsafe targets before fetching attacker-controlled URLs. However, the validation only blocks a small set of exact host strings such as `localhost` and `127.0.0.1`. It does not normalize hostnames, resolve DNS, parse numeric IPv4 variants, or validate the final resolved IP address before making the request. As a result, URLs such as the following bypass the protection and still reach loopback services: ```text http://localhost.:8765/ http://127.1:8765/ http://0177.0.0.1:8765/ http://0x7f000001:8765/ http://2130706433:8765/ ``` After the weak validation passes, `scrape_page()` calls `requests.Session.get()` on the attacker-controlled URL. This allows an attacker who can influence URLs passed to `scrape_page`, `crawl`, or `extract_text` to induce SSRF requests against loopback-only services. This is a server-side request forgery protection bypass. ### Details The affected code is in: ```text praisonaiagents/tools/spider_tools.py ``` The vulnerable flow is: ```text attacker-controlled URL -> spider_tools._validate_url(...) -> weak exact-host blocklist check -> validation passes for alternate loopback encodings -> scrape_page(...) -> requests.Session.get(attacker_url) -> loopback service is reached `


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Architectural layers (MAESTRO):