Breaking down: "We are adding a server-side URL reader to a research agent. Find the OWASP SSRF Prevention Cheat Sheet and produce a bounded implementation checklist covering redirects, DNS resolution, public versus private addresses and allowlists. Explain which controls are insufficient alone and how to preserve an explicit unavailable-source result instead of treating a failed read as evidence."

Identified 6 research target(s) to investigate; these are not established facts

Deep mode: up to 4 paid/cached/public reads plus one bounded gap-expansion pass when needed.

Web search: 4/4 planned queries attempted, 3 succeeded, 16 public page previews, 1 unavailable queries. Snippets are discovery only. Public reads spend no USDC; model and service operating costs remain separate.

Discovered 0 verified creator source(s) and 16 free public reference(s)

Claim-aware portfolio (exhaustive; bounded selection, not a claim of global optimality) selected 3/4 positive proposal(s): 3 free/cache selections + 0 paid fresh selections, predicting 5/6 claim(s) above the evidence floor with $0.000000/$0.015000 fetch USDC reserved.

Free-preview pre-check covers 5/6 sub-claims (83%). The agent may buy only claim-targeted sources and will label the answer provisional if paid evidence stays thin.

READ Server Side Request Forgery Prevention - OWASP Cheat Sheet Series - selected original public page, 0 USDC; not a cache hit.

Read extracted public text from https://cheatsheetseries.owasp.org/cheatsheets/Server_Side_Request_Forgery_Prevention_Cheat_Sheet.html - S1; quote matching establishes source grounding, not fact verification.

READ www-community/pages/controls/SSRF_Prevention_in_Nodejs.md at master · OWASP/www-community · GitHub - selected original public page, 0 USDC; not a cache hit.

Read extracted public text from https://github.com/OWASP/www-community/blob/master/pages/controls/SSRF_Prevention_in_Nodejs.md - S2; quote matching establishes source grounding, not fact verification.

READ Server-Side Request Forgery (SSRF) Prevention - selected original public page, 0 USDC; not a cache hit.

Read extracted public text from https://serversecurityauthority.com/server-side-request-forgery-prevention/ - S3; quote matching establishes source grounding, not fact verification.

Sub-claim "What does the OWASP SSRF Prevention Cheat Sheet recommend fo…": 10% covered — S1 is the OWASP SSRF Prevention Cheat Sheet but the supplied passages contain no redirect-handling recommendation; only a link title 'Unvalidated Redirects and Forwards' appears, which is topical context, not an answer. S2 has a 'Redirects' heading with no body text. The skipped Mar Benitez preview asserts the cheat sheet says to disable redirects, but skipped previews are not gathered evidence.

Sub-claim "What does the OWASP SSRF Prevention Cheat Sheet recommend fo…": 40% covered by S1, S3 — S1 states the proposed libraries were verified not to perform DNS resolution queries, which is a partial DNS-related control. S3 describes resolving once, validating the resulting IP against the allowlist, and using that resolved IP for the connection to close a rebinding window, and attributes this boundary to OWASP concerns, but S3 is a secondary source, not the cheat sheet itself. The cheat sheet's own explicit DNS-resolution recommendation is not directly quoted.

Sub-claim "How does the OWASP SSRF Prevention Cheat Sheet distinguish p…": 50% covered by S1, S3 — S1 says the application must detect at code level that a provided IP (v4+v6) is not part of official private network ranges including localhost and IPv4/v6 link-local addresses, and notes SDK support is uneven. That is a partial answer on private-address detection but does not fully state the public-vs-private distinction or the recommended handling. S3 lists RFC-1918 ranges and loopback and notes denylisting them is insufficient alone, but is secondary.

Sub-claim "What does the OWASP SSRF Prevention Cheat Sheet recommend fo…": 70% covered by S1, S3 — S1 directly recommends matching the host against an allowlist and building the request yourself from the matched entry with a fixed scheme, port, and path, and warns against copying other URL components. S3 adds that allowlist validation restricting schemes (HTTPS only), hostnames, and port ranges is structurally stronger. The core allowlist recommendation is directly answered; minor detail on allowlist construction/format is thin.

Sub-claim "According to the OWASP SSRF Prevention Cheat Sheet, which SS…": 50% covered by S1, S3 — S3 states denylist approaches blocking RFC-1918 and loopback are considered insufficient as standalone controls by OWASP because of DNS rebinding, IPv6 representations, decimal IP encoding, and URL-encoded characters, and that allowlist checks alone leave a rebinding window open. S1 supports that private-IP detection is demanding and SDK-dependent, implying it is not sufficient alone. However, the cheat sheet's own explicit statement of which controls are insufficient and why is not directly quoted.

Sub-claim "How can a server-side URL reader preserve an explicit unavai…": 0% covered — None of the supplied passages from S1, S2, or S3 address preserving an explicit unavailable-source result or distinguishing a failed read from evidence. This is an agent-design requirement not covered by the gathered OWASP material.

Coverage is below 0.5 for redirect handling and for preserving an explicit unavailable-source result, and only partial for DNS resolution and insufficient-controls rationale. However, the remaining budget is 0.015 and all skipped sources are priced at 0, so no affordable source can be recommended under the budget constraint; recommendedIds is empty. The highest-value free skipped candidates would be the OWASP Unvalidated Redirects and Forwards cheat sheet for redirect handling and the Mar Benitez post for the cheat sheet's redirect instruction, but they cannot be purchased within the remaining budget.

Final check — "What does the OWASP SSRF Prevention Cheat Sheet recommend fo…": 10% assessed by S2

Final check — "What does the OWASP SSRF Prevention Cheat Sheet recommend fo…": 30% assessed by S1, S2, S3

Final check — "How does the OWASP SSRF Prevention Cheat Sheet distinguish p…": 60% assessed by S1

Final check — "What does the OWASP SSRF Prevention Cheat Sheet recommend fo…": 100% assessed by S1

Final check — "According to the OWASP SSRF Prevention Cheat Sheet, which SS…": 40% assessed by S3

Final check — "How can a server-side URL reader preserve an explicit unavai…": 0% assessed

Final coverage assessment — The supplied passages include the OWASP SSRF Prevention Cheat Sheet (S1) and an OWASP www-community Node.js SSRF prevention page (S2), plus a secondary summary (S3). S1 directly supports allowlist-based request construction and private-address detection, but the excerpted passages do not contain the cheat sheet's redirect-handling recommendations, DNS-resolution recommendations, or explicit insufficiency-alone discussion. S2 provides only headings/fragments for redirects and DNS resolution, not the underlying recommendations. S3 is not the OWASP cheat sheet itself, though it summarizes OWASP positions on denylist insufficiency and DNS rebinding. No source addresses preserving an explicit unavailable-source result for a failed read. Coverage is therefore partial across most sub-claims and zero for the unavailable-source-result sub-claim. The assessment does not establish a complete supported answer for every requested part.

Synthesizing a grounded answer from 3 source(s)…

Relevance review returned; only checked excerpts can retain support, and review cannot raise it.

⚖️ Sources disagreed on Whether the OWASP SSRF Prevention Cheat Sheet itself states that denylists are insufficient as standalone controls and that allowlist checks alone leave a DNS-rebinding window open. — S3 Attributes these insufficiency statements to OWASP's SSRF Prevention Cheat Sheet. vs S1 The supplied Cheat Sheet excerpt contains no such insufficiency statement; it only warns that private-range IP verification is demanding and not universally supported by SDKs. → reported preference: S1 (S1 is the primary OWASP Cheat Sheet source and is authoritative for what that document says; S3 is a secondary summary whose attribution cannot be verified against the supplied S1 excerpt. S3 remains usable for the procedural resolve-once/pin detail it states in its own voice.)

Delivering qualified source excerpts; complete synthesis and per-assertion support remain unverified.

Below support/reward gate — S1, research target 1, proposed support 0% (estimate, not entailment): “Unvalidated Redirects and Forwards”

Below support/reward gate — S2, research target 1, proposed support 0% (estimate, not entailment): “Redirects”

Below support/reward gate — S1, research target 2, proposed support 30% (estimate, not entailment): “Verification of the proposed libraries has been performed to ensure that the proposed functions do not perform any DNS resolution query.”

Source-matched public excerpt (no creator reward) — S3, research target 2, proposed support 80% (estimate, not entailment): “DNS resolution control is a specialized boundary relevant where DNS rebinding is a concern: resolving the hostname once, validating the resu…”

Source-matched public excerpt (no creator reward) — S3, research target 2, proposed support 70% (estimate, not entailment): “validating the resulting IP against the allowlist, and using that resolved IP for the actual connection — rather than re-resolving at connec…”

Source-matched public excerpt (no creator reward) — S1, research target 3, proposed support 60% (estimate, not entailment): “It implies that the application must be able to detect, at the code level, that the provided IP (V4 + V6) is not part of the official privat…”

Below support/reward gate — S1, research target 3, proposed support 10% (estimate, not entailment): “Not every SDK provides a built-in feature for this kind of verification, and leaves the handling up to the developer to understand all of it…”

Source-matched public excerpt (no creator reward) — S3, research target 3, proposed support 60% (estimate, not entailment): “Denylist approaches — blocking RFC-1918 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) and loopback addresses — are considered insuffici…”

Source-matched public excerpt (no creator reward) — S3, research target 3, proposed support 50% (estimate, not entailment): “considered insufficient as standalone controls by OWASP because attackers can bypass them through DNS rebinding, IPv6 representations, decim…”

Source-matched public excerpt (no creator reward) — S1, research target 4, proposed support 90% (estimate, not entailment): “Match the host against an allowlist, and build the request yourself.”

Source-matched public excerpt (no creator reward) — S1, research target 4, proposed support 80% (estimate, not entailment): “of permitted destinations, then build the request from the entry that matched, together with a scheme, port and path the application fixes i…”

Source-matched public excerpt (no creator reward) — S3, research target 4, proposed support 80% (estimate, not entailment): “Allowlist validation restricting permitted schemes (HTTPS only), hostnames, and port ranges provides a structurally stronger boundary.”

Source-matched public excerpt (no creator reward) — S3, research target 5, proposed support 80% (estimate, not entailment): “Denylist approaches — blocking RFC-1918 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) and loopback addresses — are considered insuffici…”

Source-matched public excerpt (no creator reward) — S3, research target 5, proposed support 70% (estimate, not entailment): “validating the resulting IP against the allowlist, and using that resolved IP for the actual connection — rather than re-resolving at connec…”

Rejected 0 invalid evidence span(s) and 1 unsupported citation marker(s); rejected markers cannot receive citation rewards.

Prepared source excerpts citing 2 source(s); complete synthesis is unverified

Confidence: Low — Only source excerpts are delivered; complete synthesis and per-assertion support remain unverified. Evidence assessment: 3 sub-claims remain below the evidence threshold.

owasp.org contributed 50% - free public reference; reward share withheld

serversecurityauthority.com contributed 50% - free public reference; reward share withheld

Done. Spent $0 across 0 confirmed/simulated payment(s) to creators.