Cisco Psirt Advisories

Cisco PSIRT Advisory Checks

Answers one question well: is the software this device is running affected by a Cisco security advisory?

Read this first — an empty result is not a clean bill of health

Every tool returns one of five outcome values. Two of them look similar in the data and mean completely different things:

Never report "no advisories" as "not vulnerable". none_published means Cisco has published nothing matching that exact version string. It says nothing about unpatched-but-unpublished issues, configuration weaknesses, or anything outside Cisco's PSIRT process.

Never treat normalisation_failed or api_error as good news. Both mean the question went unasked. In a fleet sweep, check the outcome_summary counts before telling anyone the fleet is clean — devices in those two buckets were never checked at all.

The two-step chain

This server never contacts a device. It has no transport, no credentials for your network, and no way to read a version. You supply the version:

Step 1 — read the version off the device.

# Cisco platforms: pyATS
python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" run_show_command \
  '{"device_name":"cat9k-1","command":"show version"}'

# Anything else, or when pyATS has no parser: the multivendor CLI driver
python3 $MCP_CALL "python3 -u $MULTIVENDOR_MCP_SCRIPT" device_run_command \
  '{"device":"rtr-1","command":"show version"}'

Step 2 — pass it here. Full show version output is fine; the banner is parsed.

python3 $MCP_CALL "python3 -u $CISCO_PSIRT_MCP_SCRIPT" check_version \
  '{"ostype":"iosxe","version":"17.3.1"}'

Do not skip step 1 and guess a version. The server refuses to infer one — a guessed version returns advisories for software the device is not running, which is worse than no answer.

Available Tools

1. check_version — is this version affected?

python3 $MCP_CALL "python3 -u $CISCO_PSIRT_MCP_SCRIPT" check_version \
  '{"ostype":"iosxe","version":"17.3.1"}'

• ostype (required): ios | iosxe | nxos | asa | fmc | ftd | aci
• version (required): bare version or full show version output
• refresh (optional, default false): bypass the 6-hour cache

Verified: iosxe + 17.3.1 returns 122 advisories.

2. check_versions — a fleet in one call

python3 $MCP_CALL "python3 -u $CISCO_PSIRT_MCP_SCRIPT" check_versions \
  '{"devices":[{"name":"cat9k-1","ostype":"iosxe","version":"17.3.1"},
               {"name":"n9k-1","ostype":"nxos","version":"9.3(5)"}]}'

Prefer this over looping check_version. It de-duplicates by version first, so 60 devices running 12 distinct versions cost 12 API calls rather than 60 — the difference between one-third of the per-minute budget and twice it. One device failing never aborts the others.

3. check_cve — which Cisco advisories cover this CVE?

python3 $MCP_CALL "python3 -u $CISCO_PSIRT_MCP_SCRIPT" check_cve '{"cve":"CVE-2024-20353"}'

4. check_advisory — one advisory by id

python3 $MCP_CALL "python3 -u $CISCO_PSIRT_MCP_SCRIPT" check_advisory \
  '{"advisory_id":"cisco-sa-bootp-WuBhNBxA"}'

5. list_recent — what has Cisco published lately?

python3 $MCP_CALL "python3 -u $CISCO_PSIRT_MCP_SCRIPT" list_recent \
  '{"severity":"critical","start_date":"2026-01-01","end_date":"2026-07-31"}'

Verified: critical across 2026 to date returns 15 advisories.

6. psirt_status — check the budget before a sweep

python3 $MCP_CALL "python3 -u $CISCO_PSIRT_MCP_SCRIPT" psirt_status '{}'

Reports auth state, remaining rate budget, cache statistics, and which OS families are supported. Contains no credential values. Worth calling before a large sweep.

Version formats differ per family — and they contradict each other

This is the most common source of a wrong answer. The server normalises for you, but you must collect the right number in the first place.

Note the contradiction: iosxe rejects 17.3(1) while ios rejects 15.2.4E. The same-looking transformation runs in opposite directions depending on family. The server handles the conversion; pass whatever the device reported.

ACI is the trap. It wants the switch image version (15.2(3e)), not the APIC controller version — 5.2(3e) is rejected outright. Collect it from a switch, not the APIC.

IOS-XR is not supported, and this will surprise you

iosxr is not an OSType on this API. Every version tried (7.5.2, 6.6.3, 24.1.1) returns HTTP 404, against an iosxe 200 control in the same session.

This is worth flagging to the user rather than working around silently, because NetClaw can reach IOS-XR devices through pyATS — so an operator will reasonably expect the version check to work. For IOS-XR, fall back to check_cve or advisory lookup by product id, and say plainly that per-version checking is unavailable for that platform.

Where this ends and nvd-cve begins

Both answer vulnerability questions; they are not interchangeable, and neither is a substitute for the other.

Either can legitimately be empty while the other is not. Cisco may publish an advisory before an NVD entry exists; NVD may hold a CVE for which Cisco has issued no advisory. When a security question matters, check both and say which one answered.

Rate limits are shared and tight

5 calls/second and 30 calls/minute, shared across every caller of the credential. 30/minute is the real constraint. The server handles this automatically — de-duplicating by version, serving from a 6-hour cache, pacing, and backing off on 429 — but two habits defeat it:

• Looping check_version per device instead of using check_versions.
• Passing refresh: true routinely. It disables the cache. Use it during an incident when cache age is itself the question, not as a default.

What this API does not provide

Measured, not inferred from documentation — do not spend time re-testing these:

• Bug, EoX, Case and Serial-to-Info APIs return 403 under the API Console grant.
• CX Cloud returns 504 on all seven paths tried. It needs a separate tenant subscription.
• IOS-XR returns 404, as above.

Reporting results to a user

Lead with the count and the worst severity, not the whole list. Then, if the answer was none_published, say what that does and does not mean — the distinction is the point of this skill, and it is the part a reader will otherwise get wrong.

Good: "cat9k-1 on IOS-XE 17.3.1 has 122 published advisories, 4 of them Critical (highest CVSS 9.8). Recommend reviewing the Critical set first."

Good: "n9k-1 on NX-OS 9.3(5) — Cisco has published no advisory matching this exact version. That is not confirmation the device is secure; it means nothing is published for this version string."

Bad: "n9k-1 is not vulnerable." Never say this.