Microsoft Internet Explorer 4.0/4.01 JScript Scripting Engine window.external memory corruption

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.0$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Microsoft Internet Explorer 4.0/4.01. Impacted is the function window.external of the component JScript Scripting Engine. Executing a manipulation can lead to memory corruption. This vulnerability is registered as CVE-1999-1093. It is possible to launch the attack remotely. No exploit is available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability classified as critical was found in Microsoft Internet Explorer 4.0/4.01 (Web Browser). This vulnerability affects the function window.external of the component JScript Scripting Engine. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Buffer overflow in the Window.External function in the JScript Scripting Engine in Internet Explorer 4.01 SP1 and earlier allows remote attackers to execute arbitrary commands via a malicious web page.

The issue has been introduced in 04/01/1997. The weakness was published 12/31/1999 as MS98-011 as confirmed bulletin (Technet). The advisory is available at microsoft.com. This vulnerability was named CVE-1999-1093. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 1004 days. During that time the estimated underground price was around $25k-$100k.

Applying the patch MS98-011 is able to eliminate this problem. The bugfix is ready for download at microsoft.com.

The vulnerability is also documented in the databases at X-Force (1276) and Vulnerability Center (SBV-4329†). Additional details are provided at support.microsoft.com. Similar entries are available at VDB-15131 and VDB-15129. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Support

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: MS98-011

Timelineinfo

04/01/1997 🔍
08/17/1998 +503 days 🔍
12/31/1999 +501 days 🔍
12/31/1999 +0 days 🔍
05/20/2004 +1602 days 🔍
06/22/2014 +3685 days 🔍
04/20/2026 +4320 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: MS98-011
Status: Confirmed

CVE: CVE-1999-1093 (🔍)
GCVE (CVE): GCVE-0-1999-1093
GCVE (VulDB): GCVE-100-15130
X-Force: 1276 - JavaScript patch is not applied
Vulnerability Center: 4329 - [MS98-011] Buffer Overflow in the Window.External Function in Internet Explorer <= 4.01 SP1, Medium

Misc.: 🔍
See also: 🔍

Entryinfo

Created: 06/22/2014 16:49
Updated: 04/20/2026 03:31
Changes: 06/22/2014 16:49 (48), 04/07/2017 12:06 (18), 04/20/2026 03:31 (15)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!