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Vulnerability record · CVE-2001-0427 · published 18 June 2001

CVE-2001-0427: Cisco vpn 3000 concentrator improper input validation vulnerability

Cisco · Vpn 3000 Concentrator

Cisco VPN 3000 series concentrators before 2.5.2(F) allow remote attackers to cause a denial of service via a flood of invalid login requests to (1) the SSL service, or (2) the telnet service, which do not properly disconnect the user after several failed login attempts.

7.1 CVSS 2.0 High EPSS 2.5% · top 15.8% CWE-20 · Improper input validation
7.1CVSS 2.0 base score
2.5%EPSS exploitation probability, 30 days
NoNot in CISA KEV
6Affected product versions listed by NVD
6References
16 Jun 2026Last modified by NVD

Description

Cisco VPN 3000 series concentrators before 2.5.2(F) allow remote attackers to cause a denial of service via a flood of invalid login requests to (1) the SSL service, or (2) the telnet service, which do not properly disconnect the user after several failed login attempts.

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

Affected products

6 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.cisco.com/warp/public/707/vpn3k-telnet-vuln-pub.shtml PatchVendor Advisory
http://www.osvdb.org/5643
https://exchange.xforce.ibmcloud.com/vulnerabilities/6298
http://www.cisco.com/warp/public/707/vpn3k-telnet-vuln-pub.shtml PatchVendor Advisory
http://www.osvdb.org/5643
https://exchange.xforce.ibmcloud.com/vulnerabilities/6298

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2001-0427), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.