Microsoft Exchange 2000/2003 SMTP Service VERB heap-based overflow

CVSS Meta Temp Score
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CTI Interest Score
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6.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Microsoft Exchange 2000/2003. It has been rated as critical. This impacts an unknown function of the component SMTP Service. This manipulation of the argument VERB causes heap-based overflow. This vulnerability is handled as CVE-2005-0560. The attack can be initiated remotely. Additionally, an exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability classified as critical was found in Microsoft Exchange 2000/2003 (Groupware Software). Affected by this vulnerability is an unknown function of the component SMTP Service. The manipulation of the argument VERB with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Heap-based buffer overflow in the SvrAppendReceivedChunk function in xlsasink.dll in the SMTP service of Exchange Server 2000 and 2003 allows remote attackers to execute arbitrary code via a crafted X-LINK2STATE extended verb request to the SMTP port.

The bug was discovered 12/07/2004. The weakness was released 04/12/2005 by Mark Dowd and Ben Layer with ISS X-Force as MS05-021 as confirmed bulletin (Technet). It is possible to read the advisory at microsoft.com. This vulnerability is known as CVE-2005-0560 since 02/26/2005. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known.

After 1 weeks, there has been an exploit disclosed. It is possible to download the exploit at immunitysec.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 126 days. During that time the estimated underground price was around $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 18024 (MS05-021: Vulnerability in SMTP Could Allow Remote Code Execution (894549)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Windows : Microsoft Bulletins and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 90241 (Microsoft Exchange Server Remote Code Execution (MS05-021)).

Applying the patch MS05-021 is able to eliminate this problem. The bugfix is ready for download at windowsupdate.microsoft.com. A possible mitigation has been published immediately after the disclosure of the vulnerability. Attack attempts may be identified with Snort ID 3627. In this case the pattern X-LINK2STATE is used for detection. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 3367.

The vulnerability is also documented in the databases at X-Force (19843), Exploit-DB (947), Tenable (18024), SecurityFocus (BID 13118†) and OSVDB (15467†). Entries connected to this vulnerability are available at VDB-82, VDB-332, VDB-333 and VDB-427. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 6.6

VulDB Base Score: 7.3
VulDB Temp Score: 6.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

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Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 18024
Nessus Name: MS05-021: Vulnerability in SMTP Could Allow Remote Code Execution (894549)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Saint ID: exploit_info/exchange_x_link2state_bo
Saint Name: Microsoft Exchange X-LINK2STATE buffer overflow

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
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Exploit Delay Time: 🔍

Patch: MS05-021

Snort ID: 3627
Snort Message: POLICY X-LINK2STATE CHUNK command attempt
Snort Pattern: 🔍
TippingPoint: 🔍

McAfee IPS: 🔍
McAfee IPS Version: 🔍

SourceFire IPS: 🔍
ISS Proventia IPS: 🔍
PaloAlto IPS: 🔍
Fortigate IPS: 🔍

Timelineinfo

12/07/2004 🔍
02/26/2005 +81 days 🔍
04/12/2005 +45 days 🔍
04/12/2005 +0 days 🔍
04/12/2005 +0 days 🔍
04/12/2005 +0 days 🔍
04/12/2005 +0 days 🔍
04/12/2005 +0 days 🔍
04/12/2005 +0 days 🔍
04/12/2005 +0 days 🔍
04/13/2005 +0 days 🔍
04/13/2005 +0 days 🔍
04/19/2005 +6 days 🔍
05/02/2005 +13 days 🔍
07/04/2025 +7368 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: MS05-021
Researcher: Mark Dowd, Ben Layer
Organization: ISS X-Force
Status: Confirmed

CVE: CVE-2005-0560 (🔍)
GCVE (CVE): GCVE-0-2005-0560
GCVE (VulDB): GCVE-100-1351

OVAL: 🔍

CERT: 🔍
X-Force: 19843
SecurityFocus: 13118 - Microsoft Exchange Server SMTP Extended Verb Buffer Overflow Vulnerability
Secunia: 14920 - Microsoft Exchange SMTP Service Extended Verb Request Buffer Overflow, Highly Critical
OSVDB: 15467 - Microsoft Exchange Server SMTP Extended Verb X-LINK2STATE Remote Overflow
SecurityTracker: 1013687
Vulnerability Center: 7604 - [MS05-021] Microsoft Exchange Server SMTP Extended Verb Code Execution, High

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 04/13/2005 12:26
Updated: 07/04/2025 21:19
Changes: 04/13/2005 12:26 (116), 07/02/2019 11:00 (2), 01/03/2025 19:13 (16), 07/04/2025 21:19 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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