SID 1:57367

Rule Category

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

Alert Message

SERVER-WEBAPP Yealink Device Management server side request forgery attempt

Rule Explanation

This rule looks for a crafted "url" parameter value in requests to the Yealink Device Management's /premise/front/getPingData endpoint.

What To Look For

This rule looks for attempts to exploit a command injection vulnerability in the Yealink Device Management web server.

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

Rule Groups

MITRE::ATT&CK Framework::Enterprise::Initial Access::Exploit Public-Facing Application

Adversaries may attempt to take advantage of a weakness in an Internet-facing computer or program using software, data, or commands in order to cause unintended or unanticipated behavior. The weakness in the system can be a bug, a glitch, or a design vulnerability. These applications are often websites, but can include databases (like SQL), standard services (like SMB or SSH), network device administration and management protocols (like SNMP and Smart Install), and any other applications with Internet accessible open sockets, such as web servers and related services.

MITRE::ATT&CK Framework::Enterprise::Privilege Escalation::Exploitation for Privilege Escalation

Privilege escalation includes techniques that allow an attacker to obtain a higher level of permissions on the mobile device. Attackers may enter the mobile device with very limited privileges and may be required to take advantage of a device weakness to obtain higher privileges necessary to successfully carry out their mission objectives.

CVE

CVE-2021-27561 CVE-2021-27562

Additional Links

ssd-disclosure.com/ssd-advisory-yealink-dm-pre-auth-root-level-rce/

Rule Vulnerability

Server-Side Request Forgery

Server-Side Request Forgery (SSRF) attackers abuse functionality on the server to read or update internal resources. The attacker can supply or modify a URL for the server to read or submit data to. By carefully selecting the URLs, the attacker may be able to read server configuration such as AWS metadata, connect to internal services like http enabled databases or perform post requests for internal services which are not intended to be exposed.

CVE Additional Information

This product uses data from the NVD API but is not endorsed or certified by the NVD.

CVE-2021-27561

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CVE-2021-27562

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MITRE ATT&CK Framework

Tactic: Initial Access

Technique: Exploit Public-Facing Application

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