IIS / Site Server Multithread SSL Vulnerability

Bugtraq ID:	852
Class:	Race Condition Error
CVE:
Remote:	Yes
Local:	Yes
Published:	Dec 02 1999 12:00AM
Updated:	Dec 02 1999 12:00AM
Credit:	Reported to Microsoft by Wall Data. Publicized by Microsoft in Security Bulletin MS99-053, released Decemeber 2, 1999.
Vulnerable:	Microsoft Site Server Commerce Edition 3.0 i386 + Hancom Hancom Office 2007 0 - Microsoft BackOffice 4.5 - Microsoft BackOffice 4.5 + Microsoft Commercial Internet System 2.0 + Microsoft Site Server Commerce Edition 3.0 alpha - Microsoft Windows NT Enterprise Server 4.0 SP6a - Microsoft Windows NT Enterprise Server 4.0 SP6a - Microsoft Windows NT Enterprise Server 4.0 SP6 - Microsoft Windows NT Enterprise Server 4.0 SP6 - Microsoft Windows NT Enterprise Server 4.0 SP5 - Microsoft Windows NT Enterprise Server 4.0 SP5 - Microsoft Windows NT Enterprise Server 4.0 SP4 - Microsoft Windows NT Enterprise Server 4.0 SP4 - Microsoft Windows NT Enterprise Server 4.0 SP3 - Microsoft Windows NT Enterprise Server 4.0 SP3 - Microsoft Windows NT Server 4.0 SP6a - Microsoft Windows NT Server 4.0 SP6a - Microsoft Windows NT Server 4.0 SP6 - Microsoft Windows NT Server 4.0 SP6 - Microsoft Windows NT Server 4.0 SP5 - Microsoft Windows NT Server 4.0 SP5 - Microsoft Windows NT Server 4.0 SP4 - Microsoft Windows NT Server 4.0 SP4 - Microsoft Windows NT Server 4.0 SP3 - Microsoft Windows NT Server 4.0 SP3 Microsoft Site Server Commerce Edition 3.0 alpha - Microsoft BackOffice 4.5 - Microsoft BackOffice 4.5 - Microsoft IIS 4.0 - Microsoft Windows NT 4.0 - Microsoft Windows NT Enterprise Server 4.0 SP6a - Microsoft Windows NT Enterprise Server 4.0 SP6a - Microsoft Windows NT Enterprise Server 4.0 SP6 - Microsoft Windows NT Enterprise Server 4.0 SP6 - Microsoft Windows NT Enterprise Server 4.0 SP5 - Microsoft Windows NT Enterprise Server 4.0 SP5 - Microsoft Windows NT Enterprise Server 4.0 SP4 - Microsoft Windows NT Enterprise Server 4.0 SP4 - Microsoft Windows NT Enterprise Server 4.0 SP3 - Microsoft Windows NT Enterprise Server 4.0 SP3 - Microsoft Windows NT Server 4.0 SP6a - Microsoft Windows NT Server 4.0 SP6a - Microsoft Windows NT Server 4.0 SP6 - Microsoft Windows NT Server 4.0 SP6 - Microsoft Windows NT Server 4.0 SP5 - Microsoft Windows NT Server 4.0 SP5 - Microsoft Windows NT Server 4.0 SP4 - Microsoft Windows NT Server 4.0 SP4 - Microsoft Windows NT Server 4.0 SP3 - Microsoft Windows NT Server 4.0 SP3 Microsoft IIS 4.0 + Cisco Building Broadband Service Manager (BBSM) 5.0 + Cisco Building Broadband Service Manager (BBSM) 5.0 + Cisco Call Manager 3.0 + Cisco Call Manager 3.0 + Cisco Call Manager 2.0 + Cisco Call Manager 2.0 + Cisco Call Manager 1.0 + Cisco Call Manager 1.0 + Cisco ICS 7750 + Cisco ICS 7750 + Cisco IP/VC 3540 Video Rate Matching Module + Cisco IP/VC 3540 Video Rate Matching Module + Cisco Unity Server 2.4 + Cisco Unity Server 2.4 + Cisco Unity Server 2.3 + Cisco Unity Server 2.3 + Cisco Unity Server 2.2 + Cisco Unity Server 2.2 + Cisco Unity Server 2.0 + Cisco Unity Server 2.0 + Cisco uOne 4.0 + Cisco uOne 4.0 + Cisco uOne 3.0 + Cisco uOne 3.0 + Cisco uOne 2.0 + Cisco uOne 2.0 + Cisco uOne 1.0 + Cisco uOne 1.0 + Hancom Hancom Office 2007 0 + Hancom Hancom Office 2007 0 + Microsoft BackOffice 4.5 + Microsoft BackOffice 4.5 + Microsoft Windows NT 4.0 Option Pack + Microsoft Windows NT 4.0 Option Pack
Not Vulnerable:

IIS / Site Server Multithread SSL Vulnerability

The SSL ISAPI filter that ships with IIS 4 is vulnerable to an error that could allow sensitive, normally encrypted information to be transmitted in plaintext to the client. The error is in the way that the filter handles simultaneous threads. Under heavy load conditions, a multi-threaded client application could cause the server to transmit one buffer of data unencrypted and then to terminate the connection.

While the data is sent only to the client machine, the risk is that an attacker sniffing the connection could also receive the plaintext content.

IIS / Site Server Multithread SSL Vulnerability

Currently the SecurityFocus staff are not aware of any exploits for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected].

IIS / Site Server Multithread SSL Vulnerability

Solution:
Microsoft has released a patch for this issue, available at:

x86:
http://www.microsoft.com/downloads/release.asp?ReleaseID=16186
Alpha:
http://www.microsoft.com/downloads/release.asp?ReleaseID=16187

IIS / Site Server Multithread SSL Vulnerability

References:

• Microsoft Security Bulletin MS99-053: Frequently Asked Questions (Microsoft)
  
• Q244613: IIS 4.0 SSL ISAPI Filter Can Leak Single Buffer of Plaintext (Microsoft)