CVE-1999-1555

Cheyenne InocuLAN Anti-Virus Server <4.0 - Local Privilege Escalation

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-1999-1555. PoCs published by Paul Boyer.

AI-analyzed exploit summary This exploit leverages a DLL hijacking vulnerability in Cheyenne Inoculan 4.0 for Windows NT prior to SP2. By replacing the avh32dll.dll file in the shared CHEYUPD$ directory, arbitrary code execution is achieved when the service loads the malicious DLL.

Description

Cheyenne InocuLAN Anti-Virus Server in Inoculan 4.0 before Service Pack 2 creates an update directory with "EVERYONE FULL CONTROL" permissions, which allows local users to cause Inoculan's antivirus update feature to install a Trojan horse dll.

Exploits (1)

exploitdb WORKING POC VERIFIED
by Paul Boyer · c++remotewindows
https://www.exploit-db.com/exploits/19083

This exploit leverages a DLL hijacking vulnerability in Cheyenne Inoculan 4.0 for Windows NT prior to SP2. By replacing the avh32dll.dll file in the shared CHEYUPD$ directory, arbitrary code execution is achieved when the service loads the malicious DLL.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Cheyenne Inoculan 4.0 for Windows NT prior to SP2
No auth needed
Prerequisites: Access to the shared CHEYUPD$ directory · Ability to modify filelist.txt and replace avh32dll.dll
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (3)

Core 3
Core References
Exploit, Patch, Vendor Advisory mailing-list x_refsource_bugtraq
http://www.securityfocus.com/archive/1/9515
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/106
Third Party Advisory, VDB Entry vdb-entry x_refsource_xf
https://exchange.xforce.ibmcloud.com/vulnerabilities/1536

Scores

EPSS 0.0030
EPSS Percentile 53.9%

Details

Status published
Products (1)
cheyenne/inoculan_anti-virus_server < 4.0
Published Jun 11, 1998
Tracked Since Feb 18, 2026