CVE-2000-1033

Serv-U FTP Server - Unauthenticated Password Guessing Bypass via Anti-Hammering Feature

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2000-1033. PoCs published by Craig.

AI-analyzed exploit summary This Java-based exploit bypasses the anti-brute-force mechanism in FTP Serv-U by maintaining an authenticated session (anonymous or valid) while brute-forcing other credentials. It leverages the server's failure to disconnect active sessions after repeated failed login attempts.

Description

Serv-U FTP Server allows remote attackers to bypass its anti-hammering feature by first logging on as a valid user (possibly anonymous) and then attempting to guess the passwords of other users.

Exploits (1)

exploitdb WORKING POC VERIFIED
by Craig · javaremotewindows
https://www.exploit-db.com/exploits/20334

This Java-based exploit bypasses the anti-brute-force mechanism in FTP Serv-U by maintaining an authenticated session (anonymous or valid) while brute-forcing other credentials. It leverages the server's failure to disconnect active sessions after repeated failed login attempts.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: FTP Serv-U (versions affected by CVE-2000-1033)
No auth needed
Prerequisites: Network access to the FTP server · Anonymous or valid initial credentials to establish a session
MITRE ATT&CK
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (3)

Core 3
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_xf
https://exchange.xforce.ibmcloud.com/vulnerabilities/5436
Third Party Advisory, VDB Entry mailing-list x_refsource_bugtraq
http://www.securityfocus.com/archive/1/141905
Exploit, Vendor Advisory vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/1860

Scores

EPSS 0.0756
EPSS Percentile 93.7%

Details

Status published
Products (1)
cat_soft/serv-u 2.5x
Published Dec 11, 2000
Tracked Since Feb 18, 2026