Rule Category

SERVER-WEBAPP -- Snort has detected traffic exploiting vulnerabilities in web based applications on servers.

Alert Message

SERVER-WEBAPP ysoserial TypeConfuseDelegate deserialization exploit attempt

Rule Explanation

This rule looks for an upload which may be used to trigger a deserialization vulnerability.

What To Look For

This rule fires upon attempted upload of a malicious attachment to a Microsoft SharePoint server, which may be used to exploit CVE-2021-27076.

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

Rule Groups

No rule groups

CVE

Additional Links

Rule Vulnerability

Insecure Deserialization

Insecure Deserialization relates to web application security. Applications turn an object into data through serialization; the reverse of that process, deserialization, can be vulnerable to attacks when the application trusts the data that is being deserialized. Serialized data is machine readable and not encrypted; serialized user-supplied data should not be trusted. Deserialization attacks can lead to remote code execution.

CVE Additional Information

This product uses data from the NVD API but is not endorsed or certified by the NVD.
CVE-2021-27076
Loading description

MITRE ATT&CK Framework

Tactic: Execution

Technique: Execution through API

For reference, see the MITRE ATT&CK vulnerability types here: https://attack.mitre.org