CVE-2001-0669

Cisco Catalyst 6000 IDS Module and Secure IDS - HTTP Attack Evasion via Unicode Encoding

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2001-0669. PoCs published by blackangels.

AI-analyzed exploit summary This exploit targets multiple Cisco vulnerabilities, including a Unicode encoding IDS bypass (CVE-2001-0669). It sends malformed requests to trigger DoS or unauthorized access, primarily focusing on Cisco IOS and Catalyst devices.

Description

Various Intrusion Detection Systems (IDS) including (1) Cisco Secure Intrusion Detection System, (2) Cisco Catalyst 6000 Intrusion Detection System Module, (3) Dragon Sensor 4.x, (4) Snort before 1.8.1, (5) ISS RealSecure Network Sensor 5.x and 6.x before XPU 3.2, and (6) ISS RealSecure Server Sensor 5.5 and 6.0 for Windows, allow remote attackers to evade detection of HTTP attacks via non-standard "%u" Unicode encoding of ASCII characters in the requested URL.

Exploits (1)

exploitdb WORKING POC VERIFIED
by blackangels · perlremotemultiple
https://www.exploit-db.com/exploits/21100

This exploit targets multiple Cisco vulnerabilities, including a Unicode encoding IDS bypass (CVE-2001-0669). It sends malformed requests to trigger DoS or unauthorized access, primarily focusing on Cisco IOS and Catalyst devices.

Classification
Working Poc 90%
Attack Type
Dos | Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Cisco IOS, Cisco Catalyst, CiscoSecure ACS
No auth needed
Prerequisites: Network access to target device · Target running vulnerable Cisco software
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (5)

Core 5
Core References
US Government Resource third-party-advisory x_refsource_cert-vn
http://www.kb.cert.org/vuls/id/548515
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/3292
Patch, Vendor Advisory third-party-advisory x_refsource_iss
http://xforce.iss.net/alerts/advise95.php
Mailing List mailing-list x_refsource_bugtraq
http://marc.info/?l=bugtraq&m=99972950200602&w=2

Scores

EPSS 0.0439
EPSS Percentile 90.1%

Details

Status published
Products (8)
cisco/catalyst_6000_intrusion_detection_system_module
cisco/secure_intrusion_detection_system
enterasys/dragon 4.x
iss/realsecure_network_sensor 5.x
iss/realsecure_network_sensor 6.x
iss/realsecure_server_sensor 5.5
iss/realsecure_server_sensor 6.0
snort/snort 1.8.1
Published Oct 30, 2001
Tracked Since Feb 18, 2026