Microsoft IIS 3.0 SSL ISAPI Filter race condition

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.6$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Microsoft IIS 3.0. This impacts an unknown function of the component SSL ISAPI Filter. The manipulation leads to race condition. This vulnerability is documented as CVE-1999-0861. There is not any exploit available. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Microsoft IIS 3.0 (Web Server). This issue affects an unknown functionality of the component SSL ISAPI Filter. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality. The summary by CVE is:

Race condition in the SSL ISAPI filter in IIS and other servers may leak information in plaintext.

The issue has been introduced in 05/15/1997. The weakness was released 08/11/1999 with Microsoft as MS99-053 as confirmed bulletin (Technet). It is possible to read the advisory at microsoft.com. The identification of this vulnerability is CVE-1999-0861. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 818 days. During that time the estimated underground price was around $5k-$25k.

Applying the patch MS99-053 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 (3646), SecurityFocus (BID 852†) and Vulnerability Center (SBV-4030†). support.microsoft.com is providing further details. Entry connected to this vulnerability is available at VDB-14772. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.6

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: MS99-053

Timelineinfo

05/15/1997 🔍
08/11/1999 +818 days 🔍
08/11/1999 +0 days 🔍
12/02/1999 +113 days 🔍
12/02/1999 +0 days 🔍
03/24/2004 +1574 days 🔍
06/21/2014 +3741 days 🔍
04/19/2026 +4320 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: MS99-053
Organization: Microsoft
Status: Confirmed

CVE: CVE-1999-0861 (🔍)
GCVE (CVE): GCVE-0-1999-0861
GCVE (VulDB): GCVE-100-14771
X-Force: 3646
SecurityFocus: 852 - IIS / Site Server Multithread SSL Vulnerability
Vulnerability Center: 4030 - [MS99-053] Race Condition in the SSL ISAPI Filter in IIS, High

Misc.: 🔍
See also: 🔍

Entryinfo

Created: 06/21/2014 19:17
Updated: 04/19/2026 10:03
Changes: 06/21/2014 19:17 (65), 05/20/2019 16:22 (3), 04/19/2026 10:03 (16)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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