Rule Category


Alert Message

Rule Explanation

SMTP command that is specified in the alt_max_command_line_len array is detected, and its length exceeds the maximum length that is configured in the array.

What To Look For

This event is generated when SMTP_SPECIFIC_CMD_OVERFLOW is detected by Snort's preprocessor.

Known Usage

No public information

False Positives

No known false positives


Cisco Talos Intelligence Group

MITRE ATT&CK Framework

Tactic: Initial Access

Technique: Exploit Public-Facing Application

For reference, see the MITRE ATT&CK vulnerability types here:


Additional Links

Rule Vulnerability

Buffer Overflow

Buffer Overflows occur when a memory location is filled past its expected boundaries. Computer attackers target systems without proper terminating conditions on buffers, which then write the additional information in other locations in memory, overwriting what is there. This could corrupt the data, making the system behave erratically or crash. The new information could include malicious executable code, which might be executed.

CVE Additional Information

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.
SeverityHIGH Base Score7.5
Impact Score6.4 Exploit Score10.0
Confidentiality ImpactPARTIAL Integrity ImpactPARTIAL
Availability ImpactPARTIAL Access Vector
AuthenticationNONE Ease of Access