CVE-1999-1577

Internet Explorer 4.01 and 5 - Remote Code Execution via HHOpen ActiveX Control Buffer Overflow

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-1999-1577. PoCs published by Shane Hird.

AI-analyzed exploit summary This exploit targets a buffer overflow in the hhopen OLE control (hhopen.ocx) in Internet Explorer 5.0 and earlier. It uses a long string to overwrite the return address, causing arbitrary code execution via a crafted HTML page.

Description

Buffer overflow in HHOpen ActiveX control (hhopen.ocx) 1.0.0.1 for Internet Explorer 4.01 and 5 allows remote attackers to execute arbitrary commands via long arguments to the OpenHelp method.

Exploits (1)

exploitdb WORKING POC VERIFIED
by Shane Hird · textremotewindows
https://www.exploit-db.com/exploits/19521

This exploit targets a buffer overflow in the hhopen OLE control (hhopen.ocx) in Internet Explorer 5.0 and earlier. It uses a long string to overwrite the return address, causing arbitrary code execution via a crafted HTML page.

Classification
Working Poc 90%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Internet Explorer 5.0 and earlier
No auth needed
Prerequisites: Victim must visit a malicious webpage · hhopen.ocx must be present and vulnerable
devstral-2 · 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/3314
US Government Resource third-party-advisory x_refsource_cert-vn
http://www.kb.cert.org/vuls/id/29795
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/669
Third Party Advisory, VDB Entry mailing-list x_refsource_bugtraq
http://www.securityfocus.com/archive/1/28719

Scores

EPSS 0.1949
EPSS Percentile 97.0%

Details

Status published
Products (2)
microsoft/internet_explorer 4.0.1
microsoft/internet_explorer 5.0
Published Oct 31, 1999
Tracked Since Feb 18, 2026