KEV Intelligence

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2001-0537

IOS

Cisco / IOS

View live feed Monitor via API
Severity
CVSS 9.3 · High
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
68.5%
First observed
02 Jul 2026
Last observed
07 Aug 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2001-0537 is an unauthenticated vulnerability affecting Cisco IOS. HTTP server for Cisco IOS 11.3 to 12.2 allows attackers to bypass authentication and execute arbitrary commands, when local authorization is being...

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

Cisco / IOS.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

IOS

HTTP server for Cisco IOS 11.3 to 12.2 allows attackers to bypass authentication and execute arbitrary commands, when local authorization is being used, by specifying a high access level in the URL.

View vendor advisory (opens in new tab)
Published
09 Mar 2002
Exploitation Reported
21 Jun 2025
Attack vector
Remote
Complexity
—
Privileges
None
User interaction
—

Tags

nuclei_scanner ios edge

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

The Shadowserver

Recorded 21 Jun 2025

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 02 Jul 2026

First-party sensor telemetry confirms matching exploitation attempts.

Proof of concept available

Nuclei Templates

Recorded 12 Jun 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

Learn about Pro API access
Source Added
The Shadowserver First 2025-06-21 00:00 UTC
KEV Intelligence 2026-07-31 10:42 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

21

Attempts observed

4

Unique attacker IPs

4

Attacker countries

DE · JP · PL · SC

17

Sensors observed

Exploitation attempts over the last 50 days

Daily events observed by KEV Intelligence sensors

Updated 19 Aug 2026

0
2
12
0
0
0
2
1
0
1
0
0
0
0
0
0
0
2
1
0
0
0
0
0
0
0
0
0
4
2
7
2
3
2
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
1 Jul 11 Jul 21 Jul 31 Jul 19 Aug

First observed 02 Jul 2026 · Last observed 07 Aug 2026

Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.

Request telemetry access

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
2
User-Agents
4

Raw values available in Pro and Enterprise.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

Learn about Pro API access

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2001/CVE-2001-0537.yaml 25 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v2.0

9.3 High
AV:N/AC:M/Au:N/C:C/I:C/A:C

EPSS

68.5%

Weaknesses

Improper Authentication CWE-287

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Cisco IOS HTTP Configuration - Authentication Bypass

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. Observed by KEV Intelligence sensors

    Evidence-backed exploitation signal

  2. Indicators of compromise added (11)

    Indicators of compromise recorded

  3. Public PoC available

    Public proof-of-concept code published

  4. Added to KEV Intelligence KEV Feed

    High-confidence, third-party attested exploitation

  5. Nuclei template available

    Scanner coverage available

  6. CVE published

    Vulnerability disclosed publicly

  7. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

View Pro pricing Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2001-0537

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2001-0537",
  "confidence": "Confirmed",
  "cvss_score": 9.3,
  "cvss_estimated": false,
  "epss_score": 0.6845,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 21, "sensors": 17 }
}

Early warning alerts

Get alerts on high-impact exploitation

Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.

Occasional high-impact alerts. Unsubscribe anytime. See our Privacy Policy.