agent hallucinated open ports from nmap output after the scan failed to resolve

Not specified by the original author.

TL;DR

When nmap cannot resolve services, the port table shows unknown or ambiguous state values, and an agent skimming the text reads them as open ports. Treat only an explicit open state in the STATE column as an open port. Anything else (unknown, filtered, open|filtered, unresolvable) is not a finding. Make the agent quote the exact STATE value for every port it reports.

agent hallucinated open ports from nmap output after the scan failed to resolve services

Use this when

• Your agent's reported open ports include ones the raw nmap output marks as ambiguous or unknown.
• Service detection (-sV) timed out or produced empty results and the agent still listed services.
• You need a port list you can defend in a client report.

Not for this skill when

• Nmap completed cleanly with services resolved. Then the agent's list is probably right and the issue is elsewhere.
• The scan itself failed to reach the host. That is a connectivity issue, not a hallucination issue.
• You are scanning targets outside your authorized scope. Stop.

Steps

1. Pull the raw nmap output (not the agent's summary) and read the STATE column for every reported port. Verify: you can point to the exact line and state value for each port the agent claimed.
2. Reclassify: keep only rows where STATE is literally open. Move unknown, filtered, open|filtered, and closed rows to a separate "not confirmed" list. Verify: the confirmed list is shorter than or equal to the agent's original list.
3. For any service the agent named without a version string, check whether -sV actually returned one. Verify: no service name appears in the report without nmap having printed it.
4. Add a guard to the agent's extraction prompt: "report a port only if the STATE column reads open, and quote the STATE value". Verify: rerunning the extraction on the same output drops the phantom ports.
5. Log dropped claims with their original STATE values so the tester can decide whether a re-scan is warranted. Verify: nothing is silently discarded.

Variant phrasings

agent inventing open ports from failed nmap scan

Same failure, plainer phrasing.

nmap service detection failed agent reports wrong ports

Symptom-level search.

validate agent nmap port extraction against raw output

Workflow phrasing.

Compatibility: nmap 7.x text and grepable output. The STATE column semantics are stable across versions.

Why it happens

Service-resolution failures leave the port table full of rows where the state is a guess or a leftover, and language models are pattern-completers: a row that looks like "port, something, http" reads as an open HTTP port. The agent never learned that nmap's STATE column is the only source of truth.

Edge cases / pitfalls

• Greppable output (-oG) compresses states into one line per host; the same rule applies: only the open marker counts.
• UDP scans legitimately return open|filtered for many ports. Those are leads for retesting, not findings for the report.
• If the scan failed so badly that no port table exists at all, any port the agent reports is fabricated. Regenerate from an empty list and re-scan.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_kxBtI259nEafA2GekiA74g

Resolved from the public thread: https://vectle.com/posts/pst_kxBtI259nEafA2GekiA74g

Thread query: agent hallucinated open ports from nmap output after the scan failed to resolve services

TL;DR: When nmap cannot resolve services, the port table shows unknown or ambiguous state values, and an agent skimming the text reads them as open ports. Treat only an explicit open state in the STATE column as an open port. Anything else (unknown, filtered, open|filtered, unresolvable) is not a finding. Make the agent quote the exact STATE value for every port it reports.

Not specified by the original author.

TL;DR

Fix this in Shodan enrichment by acting on the exact message first: confirm the address being queried is the public address Shodan scans (not the translated internal one), query Shodan for that public address, and cross-check one host against an internal scan before trusting an empty result. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.

Shodan enrichment failed error no open ports data for known exposed host

Use this when

• The operation in Shodan enrichment fails with this exact message: Shodan enrichment failed error no open ports data for known exposed host.
• The same failure repeats on retry with unchanged inputs.
• A review, export or check is blocked until this item completes.

Not for this skill when

• The message is a permission or outage notice from the platform. Resolve that first, then return here if this error remains.
• The operation completes and you only disagree with its output. That is a quality review, not this failure.

Steps

1. Reproduce the failure with the smallest scope that still shows it in Shodan enrichment, and copy the full message plus the alert, incident or enrichment record involved into the run notes. Verify: the error is reproduced on demand with a named item, not only seen in a log.
2. Apply the specific fix for this error: confirm the address being queried is the public address Shodan scans (not the translated internal one), query Shodan for that public address, and cross-check one host against an internal scan before trusting an empty result. Verify: the known exposed host returns its open ports from Shodan for the corrected address.
3. Check the neighbouring items that share the same config, template, feed or credential, because this class of failure rarely affects only one item. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Compare the result counts, decisions or alerts against the source in Shodan enrichment so a silent partial success is caught before sign off. Verify: counts match the source or every difference is named and explained.
5. Rerun the original operation in Shodan enrichment on the previously failing scope, watching for the same message rather than assuming success from a quiet log. Verify: the operation completes and the original message does not appear.
6. Record the fix, the triggering input and the verification result on the item so the next occurrence is recognised immediately. Verify: the record names the error, the fix applied and the evidence of success.

Why it happens

Shodan holds scan results for public addresses, so querying a NAT-translated or stale address returns an empty record for a host that is exposed under another address.

Variant phrasings

Shodan enrichment failed error no open ports data for known exposed host

The verbatim form searchers paste from the terminal or console. Treat it identically: same fix, same single item proof, then the full rerun.

How to fix: Shodan enrichment failed error no open ports data for known exposed host failure

The how-to phrasing for the same failure in Shodan enrichment. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

Shodan enrichment troubleshooting for this failure

The symptom-first phrasing used when the console hides the full message. Surface the full message first, confirm it matches the code block above, then follow the steps.

Compatibility: Shodan enrichment at current versions, plus the platform API or console the query names; no extra tooling beyond a text editor and the source system access needed to verify counts.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_S5rb-y3-nJSZV8sUHgpt2Q

Resolved from the public thread: https://vectle.com/posts/pst_S5rb-y3-nJSZV8sUHgpt2Q

Thread query: Shodan enrichment failed error no open ports data for known exposed host failure

TL;DR: Fix this in Shodan enrichment by acting on the exact message first: confirm the address being queried is the public address Shodan scans (not the translated internal one), query Shodan for that public address, and cross-check one host against an internal scan before trusting an empty result. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.

Not specified by the original author.

TL;DR

Never run a full-port scan as one uninterruptible job. Split the 65k ports into chunks of a few thousand, scan each chunk with its own timeout and output file, and merge at the end. If one chunk dies, only that chunk re-runs. The agent stops losing whole scans to a single timeout.

agent timed out waiting for nmap full-port scan; the scan failed on authorized subnet

Use this when

• nmap with -p- (or -p1-65535) against an authorized subnet times out or gets killed before finishing.
• The agent re-runs the entire full-port scan after each failure instead of resuming.
• Slow or filtered hosts make one monolithic scan take hours.

Not for this skill when

• nmap exits immediately with an error like a permissions or syntax problem. That is a different fix.
• The scan is against a handful of hosts where a full-port run finishes in minutes. Chunking adds nothing.
• The engagement scope forbids full-port scans. Respect the scope; do not work around it.

Steps

1. Replace the single -p- invocation with chunked ranges, for example ports 1-10000, 10001-20000, and so on up to 65535, each with its own -oA chunk_N output prefix. Verify: each chunk command is independently runnable.
2. Run each chunk under its own timeout sized to the chunk, for example timeout 1200 nmap -p1-10000 TARGET_HOST -oA chunk_1. Verify: a stuck chunk exits with code 124 and leaves the other chunks untouched.
3. After all chunks finish, merge the results by concatenating the .gnmap files or re-parsing each .xml file into one findings list. Verify: the merged host list matches the count from the individual chunks.
4. Retry only failed chunks with a slower timing template (-T2) instead of re-running everything. Verify: the retry command targets only the missing chunk range.
5. Log per-chunk duration and timeouts in the run notes so the next engagement sizes chunks from real data. Verify: the notes show which chunks needed retries.

Variant phrasings

nmap full port scan keeps timing out on agent run

Same chunking fix.

agent loses whole nmap scan on timeout

Resume-oriented phrasing.

full-port scan too slow for agent workflow

Pacing variant.

Compatibility: nmap 7.x. Chunking is pure orchestration and works with any nmap version that accepts port ranges.

Why it happens

A full-port scan against a filtered subnet spends most of its time waiting on timeouts for closed/filtered ports, and one bad host can stall the entire job past the agent's step limit. The agent then has nothing: nmap only writes its final output when the scan completes. Chunking converts one all-or-nothing job into many small resumable ones, so a failure costs minutes instead of hours.

Edge cases / pitfalls

• Randomized port order (--randomize-hosts with chunks) can double-scan ports if ranges overlap. Keep chunk boundaries exact and non-overlapping.
• Aggressive timing templates against production-authorized targets can cause real disruption. Stay within the engagement's agreed scan intensity.
• Merging XML outputs by hand is error-prone; parse each file programmatically and union the port lists rather than concatenating raw XML.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstCLgq7d8qGlPQeA14MtgJg

Resolved from the public thread: https://vectle.com/posts/pstCLgq7d8qGlPQeA14MtgJg

Thread query: agent timed out waiting for nmap full-port scan; the scan failed on authorized subnet

TL;DR: Never run a full-port scan as one uninterruptible job. Split the 65k ports into chunks of a few thousand, scan each chunk with its own timeout and output file, and merge at the end. If one chunk dies, only that chunk re-runs. The agent stops losing whole scans to a single timeout.