CVE-2001-0669

Exp

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.

Published: 2001-10-30 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2001-0669 is rated High Exploit Risk (71.5/100): CVSS High severity, with high exploitation likelihood (EPSS 4.39%, 90th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2001-0669

EDB-ID Source Kind Published Link
21100 exploit_db edb 2001-09-05 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2001-0669

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 41.48% 4.39% -37.09%
2 2025-11-29 14.76% 41.48% +26.73%
3 2025-03-30 — 14.76% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2001-0669

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2001-0669

Affected software / configurations for CVE-2001-0669

Vendor Product Version Raw CPE
cisco catalyst_6000_intrusion_detection_system_module — cpe:2.3:a:cisco:catalyst_6000_intrusion_detection_system_module:*:*:*:*:*:*:*:*
cisco secure_intrusion_detection_system — cpe:2.3:a:cisco:secure_intrusion_detection_system:*:*:*:*:*:*:*:*
iss realsecure_network_sensor 5.x cpe:2.3:a:iss:realsecure_network_sensor:5.x:*:*:*:*:*:*:*
iss realsecure_network_sensor 6.x cpe:2.3:a:iss:realsecure_network_sensor:6.x:*:*:*:*:*:*:*
iss realsecure_server_sensor 5.5 cpe:2.3:a:iss:realsecure_server_sensor:5.5:*:*:*:*:*:*:*
iss realsecure_server_sensor 6.0 cpe:2.3:a:iss:realsecure_server_sensor:6.0:*:*:*:*:*:*:*
snort snort 1.8.1 cpe:2.3:a:snort:snort:1.8.1:*:*:*:*:*:*:*
enterasys dragon 4.x cpe:2.3:h:enterasys:dragon:4.x:*:*:*:*:*:*:*

References for CVE-2001-0669

cvelogic Threat Intelligence