CVE-2000-0570

FirstClass Internet Services server < 6.1 - Denial of Service via Long To: Mail Header

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2000-0570. PoCs published by Adam Prime.

AI-analyzed exploit summary The exploit describes a Denial of Service (DoS) vulnerability in First Class Intranet Services (FCIS) triggered by processing an email with an excessively long To: field (~1.5 MB). The provided reference links to a SecurityFocus advisory and a GitLab repository for the exploit.

Description

FirstClass Internet Services server 5.770, and other versions before 6.1, allows remote attackers to cause a denial of service by sending an email with a long To: mail header.

Exploits (1)

exploitdb WRITEUP VERIFIED
by Adam Prime · textdosmultiple
https://www.exploit-db.com/exploits/20052

The exploit describes a Denial of Service (DoS) vulnerability in First Class Intranet Services (FCIS) triggered by processing an email with an excessively long To: field (~1.5 MB). The provided reference links to a SecurityFocus advisory and a GitLab repository for the exploit.

Classification
Writeup 90%
Attack Type
Dos
Complexity
Trivial
Reliability
Theoretical
Target: First Class Intranet Services (FCIS)
No auth needed
Prerequisites: Ability to send an email to the target FCIS server
mistral-large-3 · analyzed Feb 16, 2026 Full analysis →

References (4)

Core 4
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_xf
https://exchange.xforce.ibmcloud.com/vulnerabilities/4843
Exploit, Vendor Advisory vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/1421
Third Party Advisory, VDB Entry vdb-entry x_refsource_osvdb
http://www.osvdb.org/5718
Exploit, Vendor Advisory mailing-list x_refsource_bugtraq
http://archives.neohapsis.com/archives/bugtraq/2000-06/0295.html

Scores

EPSS 0.0314
EPSS Percentile 86.6%

Details

Status published
Products (1)
centrinity/firstclass_intranet_server 5.770
Published Jun 27, 2000
Tracked Since Feb 18, 2026